tag:theconversation.com,2011:/global/topics/bats-1238/articles
Bats – The Conversation
2024-02-06T16:34:20Z
tag:theconversation.com,2011:article/222767
2024-02-06T16:34:20Z
2024-02-06T16:34:20Z
We’ve found out how earless moths use sound to defend themselves against bats – and it could give engineers new ideas
<figure><img src="https://images.theconversation.com/files/573732/original/file-20240206-20-zrb59g.jpg?ixlib=rb-1.1.0&rect=26%2C40%2C4466%2C2950&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Ermine moths are deaf, but have an intricate wing structure that protects them from bats by producing warning clicks when they fly.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/detailed-closeup-on-white-speckled-yponomeuta-2169581991">HWall/Shutterstock</a></span></figcaption></figure><p>An acoustic battle between <a href="https://www.annualreviews.org/doi/10.1146/annurev-ento-121510-133537">bats and their insect prey</a> has been raging in the night skies for over 65 million years. Many different techniques are used, and <a href="https://www.pnas.org/doi/10.1073/pnas.2313549121">our new study</a> reveals the fascinating strategy of the small, deaf ermine moth, which has evolved a tiny wing structure that produces warning sounds. We hope this insight could inspire engineers to create new technology.</p>
<p>Bats count on their secret weapon, <a href="https://www.bats.org.uk/about-bats/flight-food-and-echolocation">echolocation</a>, to find and catch their flying prey, and in response, nocturnal insects have evolved interesting defences. Many silk moths, for instance, rely on a kind of <a href="https://doi.org/10.1073/pnas.2014531117">sound-absorbing stealth cloak</a> that makes them “disappear” from bat sonar. Some large moth species have <a href="https://doi.org/10.1016/j.cub.2021.08.038">evolved reflective decoys</a> that draw bat attacks away from their body and towards the tips of their wings.</p>
<p>The next level of defence is <a href="https://www.annualreviews.org/doi/10.1146/annurev-ento-121510-133537">ears</a> that allow insects, including many moths, to pick up bat echolocation calls and fly out of harm’s way. They can also use their sensory awareness of location to blast an attacking bat with ultrasonic sounds that deter or confuse their biosonar. </p>
<p>However, scientists have long been puzzled about the many earless moths that cannot detect their predators and are too small for decoys. How do they protect themselves? </p>
<p>We recently discovered that <a href="https://research-information.bris.ac.uk/ws/portalfiles/portal/185355664/tymbals.pdf">even earless moths</a>, such as <a href="https://butterfly-conservation.org/moths/white-ermine">ermine moths</a> (<em>Yponomeuta</em>), use acoustic signals as a defence against bat attacks. These moths have a tiny structure in their hind wings which creates a powerful ultrasonic signal that jams the echolocating sonar of bats.</p>
<p>Because these moths don’t have hearing organs, they are not aware of their unique defence mechanism, and nor can they control it. Instead, the sound production mechanism is coupled to the flapping of their wings.</p>
<h2>Protective wing beats</h2>
<p>When we studied the ermine moth’s wing under a microscope, it became clear that one part of the wing stands out from the rest. While most of it is covered by small hairs and scales, one patch of wing is clear and located adjacent to a corrugated structure of ridges and valleys. In our new study, we found this structure produces sound perfectly tuned to confuse bats. </p>
<figure class="align-center ">
<img alt="Pipistrelle bat flying on wooden ceiling of house in darkness" src="https://images.theconversation.com/files/573422/original/file-20240205-21-ssex63.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/573422/original/file-20240205-21-ssex63.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/573422/original/file-20240205-21-ssex63.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/573422/original/file-20240205-21-ssex63.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/573422/original/file-20240205-21-ssex63.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/573422/original/file-20240205-21-ssex63.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/573422/original/file-20240205-21-ssex63.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Bats such as this pipistrelle use echolocation to hunt.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/pipistrelle-bat-pipistrellus-flying-on-wooden-1018158514">Rudmer Zwerver/Shutterstock</a></span>
</figcaption>
</figure>
<p><a href="https://dosits.org/science/sound/what-is-sound/">Sound is a pressure wave</a> that travels through a fluid or solid and requires a displacement of this medium, usually a vibration, to produce noise. Large vibrating surfaces over cavities are <a href="https://cmtext.indiana.edu/acoustics/chapter1_resonance.php">good for amplifying sound</a> – a good example is a tymbal drum, which has a taught skin stretched over a cavity. As the drum skin is struck by a drumstick, the skin vibrates at its natural frequencies and transmits these vibrations into the surrounding air as sound.</p>
<p>In ermine moths, the clear patch in the hind wing serves as the drum skin, while the corrugated structure of valleys and ridges act as drumsticks. During flight, the moth’s wing makes the ridges snap one after the other in a sequence. Each snap makes the clear patch, known as an <a href="https://research-information.bris.ac.uk/en/publications/a-bioinspired-mechanical-model-of-the-ultrasonic-clicks-produced-">aeroelastic tymbal</a>, vibrate and amplifies the sound volume.</p>
<p>Recordings we made of ermine moths found their wings make clicking noises during flight, which we could detect using a bat detector that converts ultrasound into sound audible to humans.</p>
<p>Using 3D X-ray and a sophisticated microscope technique called <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6961134/#:%7E:text=The%20primary%20functions%20of%20a,3D%20reconstructions%20of%20imaged%20samples.">confocal microscopy</a>, our study’s lead author, Hernaldo Mendoza Nava, mapped out the intricate properties of the materials that make these moths’ aeroelastic tymbals. We then used computer simulations to test our hypothesis that the deformations of the corrugations stimulate the wing’s membrane in a way that produces sound. These simulations produced a sound that matched our recordings of the moths’ clicks in frequency, structure, amplitude and direction.</p>
<p>Some eared moths can make similar warning sounds, but none of them (so far) have been shown to do this with an aeroelastic tymbal. </p>
<p>To our team of biologists and engineers, these wing structures are fascinating because they rely on a mechanism that we teach our engineering students to avoid. “Snap through” is an example of a <a href="https://www.egr.msu.edu/classes/me471/thompson/handout/class07_2005S_Buckling.pdf">buckling instability</a> – when a structure loses stability when loaded, and suddenly snaps into a different state.</p>
<p>In a buckling instability, the material doesn’t break but the structure usually loses stiffness and can even collapse. This can have catastrophic consequences for any structure that carries load, such as buildings, bridges and aeroplanes.</p>
<h2>Inspired by nature</h2>
<p>Historically, structures were made to be rigid enough to withstand external forces. Over the last decade, researchers and engineers have started to question this default position, and have begun to use buckling instabilities to create structures with new capabilities. </p>
<p>One example is engineers designing <a href="https://www.nature.com/collections/aabiaicgej#:%7E:text=Traditionally%2C%20structures%20were%20constructed%20to,and%20maintain%20its%20desired%20form.">morphing structures</a> <a href="https://www.cambridge.org/core/journals/aeronautical-journal/article/abs/morphing-skins/912AB6CFD2C2075099CC5D362D8BCB60">for future aircraft wings</a> that autonomously adapt their shape to perform better when the environment changes. The aeroelastic tymbal of ermine moths embodies this concept and demonstrates how nature can be an inspiration for new technology.</p>
<p>Our hope is that these deaf moths’ aeroelastic tymbals will encourage new developments in engineering domains such as acoustic structural monitoring, where structures give off sound when overloaded. This is often used to check the safety of infrastructure. It could also lead to innovations in <a href="https://en.wikipedia.org/wiki/Soft_robotics">soft robotics</a>, where the robots are made of fluids and gels instead of metal and plastics.</p><img src="https://counter.theconversation.com/content/222767/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Marc Holderied receives funding from the Biotechnology and Biological Sciences Research Council (grant no. BB/N009991/1) and the Engineering and Physical Sciences Research Council (grant no. EP/T002654/1). We thank Diamond Light Source for access
to beamline I13 (proposal MT17616) and to Dr. Shashi Marathe and Kaz Wanelik for their assistance at the facility. We thank Daniel Robert for access to and support with Laser Doppler vibrometry.</span></em></p><p class="fine-print"><em><span>Alberto Pirrera has received funding for this research from the Engineering and Physical Sciences Research Council (grant no. EP/M013170/1).</span></em></p><p class="fine-print"><em><span>Rainer Groh has received funding from the Royal Academy of Engineering (grant no. RF/201718/17178) for this research. Hernaldo Mendoza Nava, a PhD student who worked on this project for his thesis, was funded by the Science and Technology National Council (CONACYT-Mexico, CVU/studentship no. 530777/472285) and the Engineering and Physical Sciences Research Council through the EPSRC Centre for Doctoral Training in Advanced Composites for Innovation and Science (grant no. EP/L0160208/1).</span></em></p>
The ermine moth’s wing structures are fascinating because they rely on a mechanism we teach our engineering students to avoid
Marc Holderied, Professor in Sensory Biology, University of Bristol
Alberto Pirrera, Professor of Nonlinear Structural Mechanics, University of Bristol
Rainer Groh, Senior Lecturer in Digital Engineering of Structures, University of Bristol
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/221352
2024-02-05T13:34:48Z
2024-02-05T13:34:48Z
How bats ‘leapfrog’ their way home at night – new research
<figure><img src="https://images.theconversation.com/files/572171/original/file-20240130-27-o1vlrb.jpg?ixlib=rb-1.1.0&rect=0%2C10%2C3413%2C2539&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The greater horseshoe bat is one of the UK's 18 bat species. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/flying-bat-hunting-forest-greater-horseshoe-1494098204">Rudmer Zwerver/Shutterstock</a></span></figcaption></figure><p>A silent ballet takes place above our heads at night as Britain’s bat populations leave their roosts to forage for food. Although their initial movement away from roosts is fairly well understood, until recently little was known about how they returned home. </p>
<p>But our <a href="https://link.springer.com/article/10.1007/s11538-023-01233-5">new research</a> shows how bats may use a “leap-frogging” motion to make their way home, something which could help conservationists in future.</p>
<p>As they flit through the darkness, bats play a crucial role in the health of our ecosystems. From keeping insect populations in check to dispersing seeds and pollinating plants, they provide a multitude of benefits. </p>
<p>In the UK alone, the 18 bat species devour agricultural pests such as cockchafers with impressive efficiency. So, it is imperative that we not only understand and appreciate bats, but also actively support and safeguard their populations for the wellbeing of our planet.</p>
<p>But bat populations are vulnerable to pollution, climate change and loss of roosting locations. Habitat fragmentation and light pollution can also interrupt how bats feed. This is particularly important during the maternity season <strong>in early summer</strong>, when bats gather together to have and raise their young.</p>
<p>An integral aspect of effective bat conservation lies in unravelling the mysteries of how bats move. This not only helps us understand how bats navigate and use their environment, but also helps in identifying and protecting their roosts. </p>
<h2>Radio-tracking</h2>
<p>Conventional methods for pinpointing bat roosts primarily hinge on radio-tracking surveys. This arduous process involves capturing bats, attaching small radio transmitters to them before releasing them and following the signals throughout the night. </p>
<p>Our team conducted a radio-tracking survey in Devon which monitored 12 greater horseshoe bats over 24 nights. The trajectories of seven of those bats over 14 nights were extracted from the data for analysis, ensuring that in each case, a bat’s beginning and ending roost were the same.</p>
<p>Using this data, we measured the population’s average distance from the roost. We found two distinctive patterns in the data we analysed: an initial spread of bats within the first one to two hours after sunset and a gradual return to the roost afterwards.</p>
<p>The initial spread reflects the expected random dispersal of bats leaving their roosts to forage after sunset. The return to the roost, occurring two to eight hours after sunset, is more complicated. </p>
<p>This prompted us to explore two potential mechanisms influencing the bats’ return. First, a “pull mechanism”, where the roost attracts the bats home, and second, a mechanism pushing the bats who range furthest away back to the roost.</p>
<p>We modelled the pushing mechanism as a leapfrog process. Imagine this as a cascade effect, where the outermost bats begin their return. Once the “outer” bats have passed or “leapt over” bats that are closer to the roost, the “inner” bats become the furthest out causing them to return too.</p>
<p>This motion unfolds systematically, like a synchronised dance, as each bat from the periphery of the foraging range follows suit in returning to the roost after being “leapfrogged”.</p>
<p>But what causes the bats to return in this manner? One plausible explanation underscores how bats rely on each other for effective navigation, like tiny radar signals. If a bat experiences prolonged silence or predominantly hears calls from one direction, it might decide to move closer to the roost, anticipating the presence of other colony members. </p>
<p>But a bat might return more slowly, prolonging foraging, if it perceives the presence of bats beyond its current location. So, it is the outer bats that would drive the return as they would not be surrounded by calls.</p>
<h2>How does this research help bats?</h2>
<p>The significance of these findings extends beyond just describing the movements of bats. They have laid the foundation for work that promises easier discovery of new bat roosts, potentially reducing the need for labour-intensive bat tracking surveys in the future. </p>
<p>One of the immediate effects of our research includes informing a measurement of the “core sustenance zone” for greater horseshoe bats. This is where most of their foraging occurs, so it’s important in bat ecology, conservation and construction planning.</p>
<p>The leapfrogging mechanism also allows us to ascribe intention to bat movements. Namely, through using surrounding bat calls they can identify where the population is relative to their position, suggesting whether or not they are on the periphery of the group, which is an indicator of their vulnerability. Should they be furthest from the roost they move back towards the bulk of the population and closer to the roost.</p>
<p>While these interpretations hold promise, further rigorous testing is essential. And we need to think about the safety and wellbeing of the bat population.</p>
<p>Our observations are also specific to greater horseshoe bats during the summer months. Different bat species have distinct flight patterns and habitat preferences, with the same species displaying diverse behaviours at different times of the year. </p>
<p>So, while we have taken some crucial first steps, we still have a lot of work to do in unravelling the characteristics of bat motions in general.</p><img src="https://counter.theconversation.com/content/221352/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Fiona Mathews receives funding from Devon Area of Outstanding Natural Beauty, Devon County Council and the Natural Environment Research Council. She is affiliated with the UK Mammal Society, Mammal Conservation Europe, Ecotype Genetics and Ecology Search Services Ltd. </span></em></p><p class="fine-print"><em><span>Thomas Woolley does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Maths plays a crucial role in new research which finds that bats “leapfrog” their way home at night.
Thomas Woolley, Senior Lecturer in Applied Mathematics, Cardiff University
Fiona Mathews, Professor of Environmental Biology, University of Sussex
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/215811
2024-01-25T20:46:19Z
2024-01-25T20:46:19Z
Flying foxes pollinate forests and spread seeds. Here’s how we can make peace with our noisy neighbours
<figure><img src="https://images.theconversation.com/files/555448/original/file-20231023-17-y6qvdg.jpeg?ixlib=rb-1.1.0&rect=0%2C36%2C4031%2C2981&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Tolga Bat Hospital</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Flying foxes. Megabats. Fruit bats. Whatever name you choose, these fox-faced creatures are remarkable. Our four species help <a href="https://doi.org/10.1111/aec.13143">pollinate eucalyptus trees</a> in eastern Australia, spread the seeds of rainforest trees, and make our summer skies spectacular. They’re some of the largest bats in the world. </p>
<p>The endangered spectacled flying fox (<em>Pteropus conspicillatus</em>), for instance, evolved alongside northern Queensland’s tropical rainforests in the Wet Tropics. They <a href="http://ebookcentral.proquest.com/lib/jcu/detail.action?docID=312874">carry rainforest fruits</a> further than any other species – even cassowaries – and fly up to 100 kilometres a night. Many trees produce fresh pollen and lots of nectar at night to attract our only nocturnal pollinators. </p>
<p>Sadly, flying foxes can evoke fear and loathing. Elsewhere in the Asia-Pacific, six species of <a href="https://www.iucnredlist.org/search?query=pteropus&searchType=species">flying fox</a> have already gone extinct, due to hunting and other human pressure. If Australia’s species go extinct, some of our trees may well go with them. </p>
<p>But as my <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/inc3.26">research shows</a>, we can learn to live alongside these gentle creatures of the night. Here’s how.</p>
<h2>Why are flying foxes feared?</h2>
<p>Flying foxes are considered a “<a href="https://conbio.onlinelibrary.wiley.com/doi/10.1111/cobi.13513">conflict species</a>”, alongside crocodiles, dingoes, snakes and sharks. That is, our fear of these species can push us to take lethal action against them. </p>
<p>Bats can be an easy target. Consider this headline: “23 bat attacks as warning issued”, which ran in the <a href="https://www.cairnspost.com.au/news/cairns/experts-issue-safety-guide-after-23-bat-attacks-in-cairns/news-story/36deefce751690a53ca49dca0e55dc5d">Cairns Post</a> in October. The story was exaggerated – bats weren’t deliberately attacking people. They were being handled and got spooked. But headlines like this are common. </p>
<p>Our perceptions shape reality. That means it takes some work to overcome ancient fear, even if irrational, such as blood-sucking vampire bats. But there are other concerns: fear of disease or annoyance at bat poo splattering clothes on the line or falling into swimming pools. Then there’s the noise of a thousand squabbling flying foxes in a roost. </p>
<p>In the 1930s, Sir Francis Ratcliffe was contracted by the Commonwealth government to sort out “<a href="http://www.jstor.org.elibrary.jcu.edu.au/stable/993">the problem</a>” of flying foxes – essentially, culling them. This response is, sadly, common. For the past century, we have seen these large bats as pests. We drive them off or kill them <em>en masse</em>. </p>
<p>Electric wires were used to kill many spectacled flying foxes to prevent them eating lychees in the 1990s, until it became illegal. In one infamous case, 18,000 were <a href="http://envlaw.com.au/flying-fox-case/">killed at an orchard</a> south of Cairns. This killing led to a court victory, making it illegal to electrocute flying foxes. </p>
<p>Even now, killing of some species can be permitted under Queensland law, though all culls will become illegal from 2026. </p>
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Read more:
<a href="https://theconversation.com/not-in-my-backyard-how-to-live-alongside-flying-foxes-in-urban-australia-59893">Not in my backyard? How to live alongside flying-foxes in urban Australia</a>
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<p>The spectacled flying fox is not doing well. The population <a href="https://doi.org/10.1038/s41598-018-22294-w">fell sharply</a> from around 320,000 in 2004 to only 78,000 in 2018. Another 23,000 animals died in Cairns in 2018 during an <a href="https://www.animalecologylab.org/ff-heat-stress-forecaster.html">extreme heat event</a> linked to global warming. </p>
<p>Scientists know how to help the species recover by protecting their camps and food resources, and improving the survival rates of babies. </p>
<p>Unfortunately, there is constant pressure from their human neighbours to “do something” about flying foxes in backyards and parks. This push-back makes it harder for us to help the species recover. Even now, some <a href="https://kap.org.au/project/flying-foxes/">politicians</a> want them eliminated.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/565665/original/file-20231214-27-d6iq08.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="spectacled flying foxes in tree" src="https://images.theconversation.com/files/565665/original/file-20231214-27-d6iq08.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/565665/original/file-20231214-27-d6iq08.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/565665/original/file-20231214-27-d6iq08.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/565665/original/file-20231214-27-d6iq08.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/565665/original/file-20231214-27-d6iq08.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/565665/original/file-20231214-27-d6iq08.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/565665/original/file-20231214-27-d6iq08.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Spectacled flying foxes gather in noisy social roosts – but their presence is often feared or found annoying.</span>
<span class="attribution"><span class="source">Cre8 design/Shutterstock</span></span>
</figcaption>
</figure>
<h2>So what can we do?</h2>
<p>For many years, authorities attempted to move flying fox camps away from, say, a suburb out to other areas. But dispersal techniques <a href="https://www.publish.csiro.au/paper/ZO20043">rarely work</a>, cost a lot of money, and usually just move the problem to other backyards. </p>
<p>We now know there are better ways of reducing conflicts between humans and these megabats. One way is to <a href="https://doi.org/10.7882/AZ.2022.014">trim back trees</a> near the camps, removing overhanging branches so the bats do not roost over backyards. </p>
<p>If these actions don’t solve the issue, planting shrubs or erecting barrier fences as buffers between flying fox roosts and residents can help. </p>
<p>Lastly, if buffers don’t work, councils or wildlife authorities may attempt to move the camps. </p>
<p>In some areas, state governments and councils provide subsidies to cover swimming pools, pressure-clean paths, and cover crops with nets – which are still cheaper than trying to move the bats away from camps. These types of actions can go a long way towards changing public attitudes. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/565666/original/file-20231214-22-px5r3i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="grey headed flying fox drinking from pond" src="https://images.theconversation.com/files/565666/original/file-20231214-22-px5r3i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/565666/original/file-20231214-22-px5r3i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/565666/original/file-20231214-22-px5r3i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/565666/original/file-20231214-22-px5r3i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/565666/original/file-20231214-22-px5r3i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/565666/original/file-20231214-22-px5r3i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/565666/original/file-20231214-22-px5r3i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Showing people how remarkable these creatures are can help tackle scepticism.</span>
<span class="attribution"><span class="source">Frank Martins/Shutterstock</span></span>
</figcaption>
</figure>
<h2>Of bats and disease</h2>
<p>Stories about the value of flying foxes to all of us and our natural environment can help. American conservation scientist Anne Toomey has observed how important it is for scientists to <a href="https://doi.org/10.1016/j.biocon.2022.109886">use narratives</a> to help protect species.</p>
<p>Let’s take disease. This crops up a lot. Flying foxes, like other bats, have <a href="https://www.science.org/content/article/how-bats-have-outsmarted-viruses-including-coronaviruses-65-million-years">remarkable immune systems</a>. They can live perfectly happily with viruses which would lay us out for weeks – or worse. </p>
<p>This is a fact. But we often attach a narrative to it – namely, that bats are dangerous. We don’t attach the same narrative to cats, even though these beloved pets often carry <a href="https://doi.org/10.1071/WR20089">toxoplasmosis</a>, a protozoan parasite which can cause disease. </p>
<p>If you are not an experienced bat handler or carer, the story should be this: don’t touch bats you find. Instead, contact bat and wildlife carers such as the <a href="https://www.wires.org.au/">Wildlife Rescue Service</a> or, if you’re in Far North Queensland, places like the <a href="https://tolgabathospital.org/">Tolga Bat Hospital</a>.</p>
<p>Fear of bats intensified 12 years ago, when the <a href="http://dx.doi.org/10.1016/j.coviro.2016.02.004">Hendra virus</a> infected and killed several vets treating horses with the virus. While bats can carry the virus, they cannot transmit it directly to humans. And better still, we now <a href="https://doi.org/10.1016/j.onehlt.2020.100207">have a vaccine</a> preventing Hendra virus in horses.</p>
<p>Avoiding other pathogens such as Australian bat lyssavirus is easy – people who have to handle bats <a href="https://www1.health.gov.au/internet/main/publishing.nsf/Content/cdna-song-abvl-rabies.htm">get vaccinated</a> against lyssavirus. Wearing protective equipment such as gloves also prevents transmission of diseases. </p>
<p>If we know more about the importance of these majestic night-fliers – and if we find better ways of reducing human-wildlife conflicts – we can still save these creatures. After all, their biggest threat is us. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/our-laws-failed-these-endangered-flying-foxes-at-every-turn-on-saturday-cairns-council-will-put-another-nail-in-the-coffin-141116">Our laws failed these endangered flying-foxes at every turn. On Saturday, Cairns council will put another nail in the coffin</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/215811/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Noel D. Preece is lead scientist for the national recovery team for the endangered spectacled flying fox, and a non-executive director of Terrain NRM Ltd. He is also a director of a specialist environmental consulting firm, Biome5 Pty Ltd.</span></em></p>
If a colony of flying foxes sets up in your backyard, you might be annoyed – or concerned. But these gentle bats are vital to our forests.
Noel D. Preece, Adjunct Asssociate Professor, James Cook University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/220756
2024-01-09T20:18:23Z
2024-01-09T20:18:23Z
Why don’t fruit bats get diabetes? New understanding of how they’ve adapted to a high-sugar diet could lead to treatments for people
<figure><img src="https://images.theconversation.com/files/568452/original/file-20240109-23-jjo6l0.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2376%2C1442&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fruit bats have honed their sweet tooth through adaptive evolution.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/fruit-bat-feeding-in-a-tree-royalty-free-image/1293525000">Keith Rose/iStock via Getty Images Plus</a></span></figcaption></figure><p>People around the world eat too much sugar. When the body is unable to process sugar effectively, leading to excess glucose in the blood, this can result in diabetes. According to the World Health Organization, diabetes became the <a href="https://www.who.int/news-room/fact-sheets/detail/the-top-10-causes-of-death">ninth leading cause of death</a> in 2019.</p>
<p>Humans are not the only mammals that love sugar. Fruit bats do, too, eating up to <a href="https://dem.ri.gov/sites/g/files/xkgbur861/files/programs/bnatres/fishwild/outreach/critter-kits/bat-ex-benefits.pdf">twice their body weight</a> in sugary fruit a day. However, unlike humans, fruit bats thrive on a sugar-rich diet. They can <a href="https://doi.org/10.1007/s00360-019-01242-8">lower their blood sugar faster</a> than bats that rely on insects as their main food source.</p>
<p>We are a team of <a href="https://www.menlo.edu/about/find-an-expert/wei-gordon/">biologists</a> and <a href="https://scholar.google.com/citations?user=kkrPGvcAAAAJ&hl=en">bioengineers</a>. Determining how fruit bats evolved to specialize on a high-sugar diet sent us on a quest to approach diabetes therapy from an unusual angle – one that sent us all the way to Lamanai, Belize, for the <a href="https://www.batcon.org/belize-bat-a-thon/">Belize Bat-a-thon</a>, an annual gathering where researchers collect and study bats.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/568470/original/file-20240109-29-2hgb6j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two people wearing face masks, one with a headlamp and one holding a small bat up to the camera" src="https://images.theconversation.com/files/568470/original/file-20240109-29-2hgb6j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/568470/original/file-20240109-29-2hgb6j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/568470/original/file-20240109-29-2hgb6j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/568470/original/file-20240109-29-2hgb6j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/568470/original/file-20240109-29-2hgb6j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/568470/original/file-20240109-29-2hgb6j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/568470/original/file-20240109-29-2hgb6j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Authors Nadav Ahituv, left, and Wei Gordon.</span>
<span class="attribution"><span class="source">Wei Gordon</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>In our <a href="https://doi.org/10.1038/s41467-023-44186-y">newly published research</a> in Nature Communications, we and colleagues <a href="https://netbiolab.org/w/People:SB_Baek">Seungbyn Baek</a> and <a href="https://scholar.google.com/citations?user=H4jO_DQAAAAJ&hl=en">Martin Hemberg</a> used a technology that analyzes the DNA of individual cells to compare the unique metabolic instructions encoded in the genome of the Jamaican fruit bat, <em>Artibeus jamaicensis</em>, with those in the genome of the insect-eating big brown bat, <em>Eptesicus fuscus</em>. </p>
<p><a href="https://doi.org/10.1038/nature11247">Approximately 2% of DNA</a> is composed of genes, which are segments of DNA that contain the instructions cells use to create certain traits, such as a <a href="https://doi.org/10.1016/j.acthis.2020.151503">longer tongue in fruit bats</a>. The other 98% are segments of DNA that regulate genes and determine the presence and absence of the traits they encode.</p>
<p>To understand how fruit bats evolved to consume so much sugar, we wanted to identify the genetic and cellular differences between bats that eat fruit and bats that eat insects. Specifically, we looked at the genes, regulatory DNA and cell types in two significant organs involved in metabolic disease: the pancreas and the kidney. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/568363/original/file-20240109-25-d0snov.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Four male *Artibeus jamaicensis* and four male *Eptesicus fuscus* bats were put in a fast then fed fruit or worms, respectively, or no meal before analyzing the cells and genes of their kidney and pancreas." src="https://images.theconversation.com/files/568363/original/file-20240109-25-d0snov.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/568363/original/file-20240109-25-d0snov.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=244&fit=crop&dpr=1 600w, https://images.theconversation.com/files/568363/original/file-20240109-25-d0snov.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=244&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/568363/original/file-20240109-25-d0snov.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=244&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/568363/original/file-20240109-25-d0snov.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=306&fit=crop&dpr=1 754w, https://images.theconversation.com/files/568363/original/file-20240109-25-d0snov.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=306&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/568363/original/file-20240109-25-d0snov.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=306&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This flowchart outlines the authors’ study methodology.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1038/s41467-023-44186-y">Wei Gordon, created with BioRender.com/Nature Communications</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><a href="https://doi.org/10.1038/s41580-020-00317-7">The pancreas</a> regulates blood sugar and appetite by secreting hormones like insulin, which lowers your blood sugar, and glucagon, which raises your blood sugar. We found Jamaican fruit bats have <a href="https://doi.org/10.1038/s41467-023-44186-y">more insulin-producing and glucagon-producing cells</a> than big brown bats, along with regulatory DNA that primes fruit bat pancreatic cells to initiate production of insulin and glucagon. Together these two hormones work to keep blood sugar levels balanced even when the fruit bats are eating large amounts of sugar.</p>
<p><a href="https://doi.org/10.1093%2Fndt%2Fgfx027">The kidney</a> filters metabolic waste from the blood, maintains water and salt balance and regulates blood pressure. Fruit bat kidneys need to be equipped to remove from their bloodstreams the large amounts of water that come from fruit while retaining the low amounts of salt in fruit. We found Jamaican fruit bats have adjusted the compositions of their kidney cells in accordance with their diet, <a href="https://doi.org/10.1038/s41467-023-44186-y">reducing the number of urine-concentrating cells</a> so their urine is more diluted with water compared with big brown bats.</p>
<h2>Why it matters</h2>
<p>Diabetes is one of the most expensive chronic conditions in the world. The <a href="https://doi.org/10.2337/dci23-0085">U.S. spent US$412.9 billion</a> in 2022 on direct medical costs and indirect costs related to diabetes.</p>
<p>Most approaches to developing new treatments for diabetes are based on traditional laboratory animals such as mice because they are easy to reproduce and study in a lab. But outside the lab, there exist mammals like fruit bats that have actually evolved to withstand high sugar loads. Figuring out how these mammals deal with high sugar loads can help researchers identify new approaches to treat diabetes.</p>
<p>By applying new cell characterization technologies on these <a href="https://theconversation.com/e-coli-is-one-of-the-most-widely-studied-organisms-and-that-may-be-a-problem-for-both-science-and-medicine-206045">nonmodel organisms</a>, or organisms researchers don’t usually use for research in the lab, we and a growing body of researchers show that nature could be leveraged to develop novel treatment approaches for disease. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/QIBMyj8ebRU?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The authors disentangle a fruit bat from a net during the Belize Bat-a-thon.</span></figcaption>
</figure>
<h2>What still isn’t known</h2>
<p>While our study revealed many potential therapeutic targets for diabetes, more research needs to be done to demonstrate whether our fruit bat DNA sequences can help understand, manage or cure diabetes in humans.</p>
<p>Some of our fruit bat findings may be unrelated to metabolism or are specific only to Jamaican fruit bats. There are <a href="https://www.britannica.com/animal/Old-World-fruit-bat">close to 200 species</a> of fruit bats. Studying more bats will help researchers clarify which fruit bat DNA sequences are relevant for diabetes treatment. </p>
<p>Our study also focused only on bat pancreases and kidneys. Analyzing other organs involved in metabolism, such as the liver and small intestine, will help researchers more comprehensively understand fruit bat metabolism and design appropriate treatments.</p>
<h2>What’s next</h2>
<p>Our team is now testing the regulatory DNA sequences that allow fruit bats to eat so much sugar and checking whether we can use them to better regulate how people respond to glucose.</p>
<p>We are doing this by <a href="https://www.youtube.com/watch?v=Cv59sjupd1Y&t=77s">swapping the regulatory DNA sequences</a> in mice with those of fruit bats and testing their effects on how well these mice manage their glucose levels.</p>
<p><em>The <a href="https://theconversation.com/us/topics/research-brief-83231">Research Brief</a> is a short take about interesting academic work.</em></p><img src="https://counter.theconversation.com/content/220756/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Wei Gordon receives funding from NSF. </span></em></p><p class="fine-print"><em><span>Nadav Ahituv is a cofounder and on the scientific advisory board of Regel Therapeutics and also received funding from BioMarin Pharmaceutical Incorporate.
Funding for this research was supported by the National Human Genome Research Institute grant R01HG012396.
</span></em></p>
Fruit bats can eat up to twice their body weight in fruit a day. But their genes and cells evolved to process all that sugar without any health consequences − a feat drug developers can learn from.
Wei Gordon, Assistant Professor of Biology, Menlo College
Nadav Ahituv, Professor, Department of Bioengineering and Therapeutic Sciences; Director, Institute for Human Genetics, University of California, San Francisco
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/213863
2023-10-22T19:01:21Z
2023-10-22T19:01:21Z
How to beat ‘rollout rage’: the environment-versus-climate battle dividing regional Australia
<p>In August, Victoria’s Planning Minister Sonya Kilkenny <a href="https://www.planning.vic.gov.au/environmental-assessments/browse-projects/willatook-wind-farm">made a decision</a> that could set a difficult precedent for Australia’s effort to get to net-zero emissions by 2050.</p>
<p>In considering the environmental effects of the proposed $1 billion <a href="https://www.willatookwindfarm.com.au/">Willatook wind farm</a> 20km north of Port Fairy in southwest Victoria, the minister ruled that the developers, <a href="https://windprospect.com.au/">Wind Prospect</a>, had to build wider buffers around the wind turbines and observe a five-month ban on work at the site over each of the two years of construction. </p>
<p>Her reason? To protect the wetlands and breeding season of the <a href="https://www.wildlife.vic.gov.au/__data/assets/pdf_file/0024/91383/Brolga.pdf">brolga</a>, a native crane and a threatened species, and the habitat of the critically endangered <a href="https://www.environment.vic.gov.au/conserving-threatened-species/threatened-species/southern-bent-wing-bat">southern bent-wing bat</a>. </p>
<p><iframe id="tc-infographic-973" class="tc-infographic" height="400px" src="https://cdn.theconversation.com/infographics/973/534c98def812dd41ac56cc750916e2922539729b/site/index.html" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>The decision shocked many clean energy developers. Wind Prospect’s managing director Ben Purcell said the conditions imposed by the minister would reduce the planned number of 59 turbines <a href="https://www.abc.net.au/news/rural/2023-08-04/willatook-wind-farm-proposal-doubt-government-recommendations/102691028">by two-thirds</a> and make the project “<a href="https://www.abc.net.au/news/rural/2023-08-04/willatook-wind-farm-proposal-doubt-government-recommendations/102691028">totally unworkable</a>”. </p>
<p>Kilkenny acknowledged that <a href="https://www.planning.vic.gov.au/environmental-assessments/browse-projects/willatook-wind-farm">her assessment</a> might reduce the project’s energy output. However, she said “while the transition to renewable energy generation is an important policy and legislative priority for Victoria”, so was “protection of declining biodiversity values”.</p>
<p>The military uses the term “blue on blue” for casualties from friendly fire. In the environmental arena we now risk “green on green” losses, <a href="https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4443474&utm_source=Sailthru&utm_medium=email&utm_campaign=Intelligencer%20-%20August%208%2C%202023&utm_term=Subscription%20List%20-%20Daily%20Intelligencer%20%281%20Year%29">and agonising dilemmas</a> as governments try to reconcile their responses to the world’s two biggest environmental problems: climate change and biodiversity loss. </p>
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<strong>
Read more:
<a href="https://theconversation.com/the-human-factor-why-australias-net-zero-transition-risks-failing-unless-it-is-fair-214064">The human factor: why Australia's net zero transition risks failing unless it is fair</a>
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<h2>The green vs green dilemma</h2>
<p>The goal of achieving net zero by 2050 requires nothing less than an economic and social transformation. That includes extensive construction of wind and solar farms, transmission lines, pumped hydro, critical mineral mines and more. </p>
<p>Australia needs to move fast – the Australian Energy Market Operator says <a href="https://www.abc.net.au/news/2023-09-17/aemo-maps-10,000km-of-high-voltage-transmission/102833156">10,000km of high-voltage transmission lines</a> need to be built to support the clean energy transition – but we are already <a href="https://www.afr.com/companies/energy/the-energy-transition-gridlocked-regulators-have-no-answers-20231009-p5eapd">lagging badly</a>. </p>
<p>The problem is that moving fast inflames what is often fierce opposition from local communities. They are especially concerned with the environmental impacts of vast electricity towers and lines running across land they love. </p>
<p>In southern New South Wales, <a href="https://www.theaustralian.com.au/nation/trandgrids-humelink-the-anguish-and-anger-behind-australias-clean-energy-plan/news-story/2a64de7aaffcd3462adaff39c9f5d485">organised groups are fighting to stop</a> the construction of a huge infrastructure project, <a href="https://www.transgrid.com.au/projects-innovation/humelink">HumeLink</a>, that seeks to build 360km of transmission lines to connect <a href="https://www.snowyhydro.com.au/snowy-20/about/">Snowy Hydro 2.0</a> and other renewable energy projects to the electricity grid. </p>
<p>Locals say the cities will get the power, while they pay the price. “No one should minimise the consequences of ‘industrialising’ Australia’s iconic locations – would we build power lines above Bondi Beach?” <a href="https://www.theaustralian.com.au/nation/trandgrids-humelink-the-anguish-and-anger-behind-australias-clean-energy-plan/news-story/2a64de7aaffcd3462adaff39c9f5d485">the Snowy Valleys Council asked</a> in a submission to a parliamentary inquiry.</p>
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<p>
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<strong>
Read more:
<a href="https://theconversation.com/why-australia-urgently-needs-a-climate-plan-and-a-net-zero-national-cabinet-committee-to-implement-it-213866">Why Australia urgently needs a climate plan and a Net Zero National Cabinet Committee to implement it</a>
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<p>Clean energy developers are caught in a perfect storm, <a href="https://www.abc.net.au/news/2023-09-22/michelle-grattan-uphill-road-angry-locals-renewables/102887426">at loggerheads with environmentalists and landholders alike</a> over environmental conditions, proper consultation and compensation, while grappling with long regulatory delays and supply chain blockages for their materials. </p>
<p>They see a system that provides environmental approval on paper but seemingly unworkable conditions and intolerable delays in practice. Does the bureaucracy’s left hand, they wonder, know what its right hand is doing?</p>
<p>Net zero, nature protection and “<a href="https://www.theaustralian.com.au/nation/politics/rollout-rage-power-struggle-and-a-shocked-minister/news-story/21aeebffca06cd116d6b077ca5a02624">rollout rage</a>” feel like a toxic mix. Yet we have to find a quick way to deliver the clean energy projects we urgently need. </p>
<h2>What is to be done?</h2>
<p>The major solution to climate change is to electrify everything, using 100% renewable energy. That means lots of climate-friendly infrastructure.</p>
<p>The major regulatory solution to ongoing biodiversity loss is to stop running down species and ecosystems so deeply that they cannot recover. Among other things, that means protecting sensitive areas, which are sometimes the same areas that need to be cleared, or at least impinged upon, to build new infrastructure.</p>
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<p>
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<strong>
Read more:
<a href="https://theconversation.com/made-in-america-how-bidens-climate-package-is-fuelling-the-global-drive-to-net-zero-214709">Made in America: how Biden's climate package is fuelling the global drive to net zero</a>
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<p>To get agreement, we need a better way than the standard project-based approval processes and private negotiations between developers and landowners. The underlying principle must be that all citizens, not just directly affected groups, bear the burden of advancing the common good. </p>
<p>As tough as these problems look, elements of a potential solution, at least in outline, are on the table. </p>
<p>These elements are: good environmental information, regional environmental planning and meaningful public participation. The government’s <a href="https://www.dcceew.gov.au/sites/default/files/documents/nature-positive-plan.pdf">Nature Positive Plan</a> for stronger environmental laws promises all three.</p>
<h2>The Albanese government’s plan</h2>
<p>Australia lags badly in gathering and assembling essential environmental information. Without it, we are flying blind. The government has <a href="https://www.aph.gov.au/About_Parliament/Parliamentary_departments/Parliamentary_Library/Budget/reviews/2023-24/Environment">established Environment Information Australia</a> “to provide an authoritative source of high-quality environmental information.” Although extremely belated, it’s a start.</p>
<p>The Nature Positive Plan may also improve the second element – regional planning – by helping it deal with “green on green” disputes through <a href="https://www.kwm.com/global/en/insights/latest-thinking/federal-environmental-law-reform-what-you-need-to-know-in-2023.html#:%7E:text=Regional%20plans%20will%20be%20built,development%20will%20be%20largely%20prohibited">its proposed “traffic light” system</a> of environmental values. </p>
<p>Places with the highest environmental values (or significant Indigenous and other heritage values) would be placed in “red zones” and be protected from development, climate-friendly or not. </p>
<p>Development would be planned in orange and green zones, but require <a href="https://www.environment.nsw.gov.au/topics/animals-and-plants/biodiversity-offsets-scheme#:%7E:text=The%20Biodiversity%20Offsets%20Scheme%20is,gains%20through%20landholder%20stewardship%20agreements.">biodiversity offsets</a> in orange zones. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/too-hard-basket-why-climate-change-is-defeating-our-political-system-214382">Too hard basket: why climate change is defeating our political system</a>
</strong>
</em>
</p>
<hr>
<p>The catch is that most current biodiversity offsets, which commonly involve putting land into reserve to compensate for land cleared, are environmental failures. </p>
<p>The government has promised to tighten these rules, but advocates ranging from <a href="https://www.smh.com.au/environment/sustainability/development-could-be-banned-in-certain-areas-amid-sweeping-recommendations-20230824-p5dz5t.html">former senior public servant Ken Henry</a> to the <a href="https://www.acf.org.au/what-the-governments-plan-to-overhaul-our-national-environment-laws-means-for-nature">Australian Conservation Foundation</a> are pushing for more. A strict approach would make offsets expensive and sometimes impossible to find, but that is the price of becoming nature-positive. </p>
<h2>The need for regional planning</h2>
<p>Good regional planning – based, say, on Australia’s <a href="https://nrmregionsaustralia.com.au/nrm-regions-map/">54 natural resource management regions</a> – would deal with a bundle of issues upfront. That approach would avoid the environmental “deaths of a thousand cuts” that occur when developments are approved one by one. </p>
<p>But regional planning will only succeed if federal and state governments allocate significant resources and work together. Australia’s record on such cooperation is a sorry one. Again, Environment Minister Tanya Plibersek is attempting a belated <a href="https://minister.dcceew.gov.au/plibersek/media-releases/regional-plans-transform-environmental-protection">fresh start</a>, but this will be a particularly rocky road.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1600710311400464385"}"></div></p>
<p>The third element – meaningful public participation – involves restoring trust in the system. This requires transparency, proper consultation, and the public’s right <a href="https://www.wilderness.org.au/news-events/epbc-act-must-enshrine-a-fair-say-for-community">to challenge decisions in the courts</a>. </p>
<p>Meaningful consultation requires time, expertise, and properly funded expert bodies that can build a culture of continuous improvement. Again, Australia’s record to date has been piecemeal and poor.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-road-is-long-and-time-is-short-but-australias-pace-towards-net-zero-is-quickening-214570">The road is long and time is short, but Australia's pace towards net zero is quickening</a>
</strong>
</em>
</p>
<hr>
<p>These reforms – better information, planning and public participation – will take time. In the meantime, the <a href="https://en.wikipedia.org/wiki/Precautionary_principle">precautionary principle</a> suggests a three-pronged approach to keeping us on track for net zero. </p>
<p>One, work proactively with developers to find infrastructure sites that avoid environmentally sensitive areas. </p>
<p>Two, speed up regulatory approvals. Fund well-resourced taskforces for both, as the gains will vastly outweigh the costs.</p>
<p>Three, be generous in compensating landowners where development is approved. Fairness comes at a cost, but unfairness will create an even higher one.</p>
<p>All this makes for a political sandwich of a certain kind. Why would government even consider it? </p>
<p>The answer lays bare the hard choice underlying modern environmental policy. We can accept some pain now, or a lot more later. The prize, though, is priceless: a clean energy system for a stable climate, and a natural environment worth passing on to future generations.</p><img src="https://counter.theconversation.com/content/213863/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Burnett is a member of the Biodiversity Council, which has the object of communicating accurate information on all aspects of biodiversity to secure and restore the future of Australia’s biodiversity.</span></em></p>
If Australia is to meet its net zero targets it must move fast and build massive industrial infrastructure. But those projects are provoking fierce hostility. Is there a way through the green dilemma?
Peter Burnett, Honorary Associate Professor, ANU College of Law, Australian National University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/213914
2023-09-29T15:41:08Z
2023-09-29T15:41:08Z
Ukraine war: Russian shelling is taking a deadly toll on urban bats
<figure><img src="https://images.theconversation.com/files/550598/original/file-20230927-27-i3qjxf.jpg?ixlib=rb-1.1.0&rect=24%2C0%2C5439%2C3645&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Many of the buildings in Kharkiv that bats roost in have been destroyed or damaged by shelling.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/demolition-demolished-apartment-buildings-city-caused-2289208005">DarSzach/Shutterstock</a></span></figcaption></figure><p>Russia’s invasion of Ukraine in February 2022 has given rise to a humanitarian crisis. <a href="https://www.unrefugees.org/emergencies/ukraine/">More than 6.2 million people</a> have fled Ukraine as a result of heavy shelling and fighting, and an additional 5.1 million people have been internally displaced. </p>
<p>But wars do not only inflict suffering on humans – animals suffer too. <a href="https://brill.com/view/journals/jaae/5/1/article-p27_4.xml">Research</a> by the <a href="https://batsukraine.org/en/bats-species-en/">Ukrainian Bat Rehabilitation Center</a> (the largest project for bat conservation, research and outreach in eastern Europe) has brought into focus the plight of bats in the war-damaged city of Kharkiv. Situated only 30km from the Russian border, Kharkiv has suffered severe damage from <a href="https://www.reuters.com/world/europe/ukraine-russia-accuse-each-other-shelling-civilians-zaporizhzhia-2023-07-15/">relentless shelling</a> throughout the conflict.</p>
<p>In 2022, shelling may have led directly to the killing of approximately 7,000 <a href="https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/animals/mammals/noctule-bat/">noctule bats</a> (<em>Nyctalus noctula</em>) – a species common throughout Europe. Nearly 3,000 more bats then became trapped inside damaged buildings, where many subsequently died. More trapped bats were found in Kharkiv in 2022 than in the preceding four years combined.</p>
<p>Despite the challenges posed by the invasion, scientists at the Ukrainian Bat Rehabilitation Center have valiantly continued their bat conservation efforts, providing care and rehabilitation for injured bats. These efforts have also given scientists the opportunity to gather data on how the invasion has affected bats and their roosting locations. </p>
<figure class="align-center ">
<img alt="The common noctule bat." src="https://images.theconversation.com/files/550596/original/file-20230927-19-2pbu8y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/550596/original/file-20230927-19-2pbu8y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=426&fit=crop&dpr=1 600w, https://images.theconversation.com/files/550596/original/file-20230927-19-2pbu8y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=426&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/550596/original/file-20230927-19-2pbu8y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=426&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/550596/original/file-20230927-19-2pbu8y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=536&fit=crop&dpr=1 754w, https://images.theconversation.com/files/550596/original/file-20230927-19-2pbu8y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=536&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/550596/original/file-20230927-19-2pbu8y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=536&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Shelling may have led to the killing of 7,000 noctule bats in Kharkiv alone in 2022.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/common-noctule-nyctalus-noctula-netopyr-rezavy-150484784">Denisa Mikesova/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Bats in trouble?</h2>
<p>Bats inhabit parts of urban areas that are particularly susceptible to attacks. Noctule bats, for instance, spend most of the winter hibernating <a href="https://link.springer.com/chapter/10.1007/978-3-319-25220-9_14">within multistorey buildings</a>, such as in cavities between concrete blocks.</p>
<p>The damage to the city began at the end of the bat hibernation season (November to April). Consequently, some of the buildings were sheltering thousands of hibernating bats when the first strikes occurred. The researchers estimate that as many as 45% of the buildings in Kharkiv that bats roost in have been completely or partially destroyed by shelling. </p>
<p>During this hibernation period, bats enter a <a href="https://thelandmarkpractice.com/bats-and-hibernation/">state of inactivity</a> where they reduce their heart rate and metabolic state. Once they have entered this state, they can take <a href="https://dnr.wisconsin.gov/newsroom/release/55886">upwards of 20 minutes</a> to wake up, so cannot respond to danger quickly.</p>
<p>From August to October, bats again gather in these buildings to mate, during a period known as “autumn swarming”. Windows left open by people as they were evacuating, or that were broken during the war, made it easy for bats to fly inside these buildings, where they subsequently became trapped. </p>
<p>During the autumn swarming period in 2022, three times as many bats were found trapped in buildings than the average in non-war years, with a death rate of around 30%.</p>
<h2>Lured into a trap</h2>
<p>In 2022, Kharkiv might also have been experiencing a higher bat population than is usual for autumn. Typically, researchers observe only a few bats in the weeks directly following the autumn swarming, a period they term the “autumn silence”. Between 2016 and 2019, they recorded sightings of fewer than 10 bats every few days during this silence.</p>
<p>However, during the same period in 2022, they reported sightings of over 100 bats on three occasions. This suggests that the usual autumn silence period may not have occurred.</p>
<p>This surge in bat numbers could have been brought about for several reasons. In the early days of the war, streetlights in Kharkiv were switched off and there was minimal lighting from houses, so the level of artificial light pollution was reduced. Artificial light pollution can disrupt bats, making them more <a href="https://www.lbp.org.uk/downloads/Publications/Management/lighting_and_bats.pdf">vulnerable to predators</a> and causing them to <a href="https://www.bats.org.uk/about-bats/threats-to-bats/lighting#:%7E:text=Artificial%20light%20falling%20on%20or,abundance%20(just%20after%20dusk).">emerge from their roosts</a> later at night.</p>
<p>The increase in bat sightings could also be explained by the growth of unmown grass and vegetation in the city during the conflict. This may have offered an <a href="https://www.sciencedaily.com/releases/2019/12/191219074744.htm">increased supply of insects</a> for the bats to feed on.</p>
<figure class="align-center ">
<img alt="A destroyed residential building after a missile rocket attack." src="https://images.theconversation.com/files/550613/original/file-20230927-19-wgneed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/550613/original/file-20230927-19-wgneed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/550613/original/file-20230927-19-wgneed.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/550613/original/file-20230927-19-wgneed.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/550613/original/file-20230927-19-wgneed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/550613/original/file-20230927-19-wgneed.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/550613/original/file-20230927-19-wgneed.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">War-damaged windows became gateways for bats to enter buildings.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/destroyed-residential-building-after-russian-missle-2319354047">Tatyana Vyc/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Protecting animals in conflict zones</h2>
<p>Hundreds of thousands of bats are estimated to hibernate in Kharkiv each year. The proportion of bats that have been killed or trapped in the city’s war-damaged environment is therefore still relatively low.</p>
<p>But this same story is probably happening throughout all of Ukraine’s war-damaged cities, resulting in many more bat fatalities. So the impact the war is having on their population is still worrying.</p>
<p>Bats play an <a href="https://www.bathealthfoundation.org/html/general_public.html">important role in the ecosystem</a>, particularly because they prey on insects. A substantial decline in bat populations has the potential to result in an <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8530310/">uptick in the population</a> of insect pests. </p>
<p>Invasive insect pests carry a substantial economic burden, imposing a yearly cost of <a href="https://www.gov.uk/government/news/worlds-first-international-plant-health-conference-to-set-global-agenda-on-biosecurity-and-address-challenges-in-plant-health#:%7E:text=economy%20and%20environment.-,The%20Food%20and%20Agriculture%20Organization%20(FAO)%20of%20the%20United%20Nations,at%20least%20USD%2070%20billion.">at least US$70 billion</a> (£57 billion) to the global economy. According to <a href="https://www.science.org/doi/10.1126/science.1201366">research</a>, the economic value of bats to the US agricultural sector alone is estimated at nearly US$23 billion annually.</p>
<p>The Ukrainian Bat Rehabilitation Center’s research has highlighted the ecological impact war can have on urban bats. However, this may apply to <a href="https://www.ifaw.org/international/press-releases/war-ukraine-biodiversity">many other key species</a> too.</p>
<p>When the time comes to repair Ukraine’s damaged cities, the significance of urban wildlife must not be overlooked. These animals are an important part of the urban environment. As people rebuild their lives, they must ensure a home is rebuilt for nature too.</p><img src="https://counter.theconversation.com/content/213914/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eleanor Harrison does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Shelling may have led to the killing of 7,000 noctule bats in the city of Kharkiv alone
Eleanor Harrison, Lecturer in Ecology, Keele University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/210028
2023-09-26T14:01:48Z
2023-09-26T14:01:48Z
World’s biggest bat colony gathers in Zambia every year: we used artificial intelligence to count them
<figure><img src="https://images.theconversation.com/files/538454/original/file-20230720-23-7sbh1p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Straw-coloured fruit bats at Kasanka National Park, Zambia.</span> <span class="attribution"><span class="source">Fabian von Poser/Getty Images</span></span></figcaption></figure><p>Everybody who visits <a href="https://kasanka.com/">Kasanka National Park</a> in Zambia during “bat season” agrees that the evening emergence of African straw-coloured fruit bats from their roost site is one of the wildlife wonders of the world. The <a href="http://speciesstatus.sanbi.org/assessment/last-assessment/02022/">bats</a> (<em>Eidolon helvum</em>) arrive at Kasanka every year around October. The numbers swell rapidly until they peak in November. By January they are gone again.</p>
<p>Once they recover from the shock of the breathtaking spectacle, everyone also converges on the same question – how many bats are there? So many fly out so fast, it seems impossible to count them. Past estimates based on visual counts have ranged from <a href="https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1365-2028.2000.00281.x">1 million</a> to <a href="https://zslpublications.onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.2005.00020.x">10 million</a>, a sign of how difficult the task is. </p>
<p>To crack the problem we clearly needed a <a href="https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecs2.4590">new approach</a>. Using an array of small video cameras, we filmed the bats leaving their roost and then developed artificial intelligence to count them. This offers an inexpensive, fast and repeatable way to count large numbers of moving animals.</p>
<p>Our average estimate for the Kasanka colony for five days in November 2019 was 857,233 bats. This makes it one of the biggest bat colonies in the world, and the most important in Africa.</p>
<p>The next question is why we wanted to count them. </p>
<h2>Why counting is important</h2>
<p>Past work on this species has shown that the ecosystem services they provide are unparalleled. They disperse seeds every night over distances of <a href="https://doi.org/10.1016/j.cub.2019.02.033">75km and more</a> – three times further than the African elephant. Larger colonies disperse more seeds and are thus more valuable in ecosystems. Unfortunately, decreases in bat numbers are being <a href="https://www.eidolonmonitoring.com/monitoring/ghana">observed</a> in places. Standardised counts are critical to distinguish between colony shifts due to <a href="https://doi.org/10.1016/j.biocon.2011.09.003">disturbance by people</a> and population-level declines that require conservation management. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/fruit-bats-the-winged-conservationists-reforesting-parts-of-africa-183274">Fruit bats: the winged 'conservationists' reforesting parts of Africa</a>
</strong>
</em>
</p>
<hr>
<p>Counting the Kasanka colony is important for another reason too. The <a href="https://doi.org/10.1111/j.1469-7998.2008.00425.x">African straw-coloured fruit bat</a> is the only long-distance migrant fruit bat on the continent. We don’t know the details of these migration routes yet, but each year we see them converging in temporary colonies, such as the one in Kasanka, and then moving on to parts unknown. Their time at these stop-over sites seems to be synchronised with peaks in local <a href="https://doi.org/10.1098/rsos.200274">food availability</a>, and larger colonies are better at <a href="https://doi.org/10.1111/1365-2435.14097">matching their timing</a> with the best food availability. </p>
<p>So large colonies indicate a healthier, more food-rich landscape, and are also key to maintaining the collective behaviour of migration.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/538455/original/file-20230720-15-2lyez1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="About a dozen bats hanging head-down on a tree branch." src="https://images.theconversation.com/files/538455/original/file-20230720-15-2lyez1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/538455/original/file-20230720-15-2lyez1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=906&fit=crop&dpr=1 600w, https://images.theconversation.com/files/538455/original/file-20230720-15-2lyez1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=906&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/538455/original/file-20230720-15-2lyez1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=906&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/538455/original/file-20230720-15-2lyez1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1138&fit=crop&dpr=1 754w, https://images.theconversation.com/files/538455/original/file-20230720-15-2lyez1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1138&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/538455/original/file-20230720-15-2lyez1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1138&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Straw-coloured fruit bats on a tree, Kasanka National Park, Zambia.</span>
<span class="attribution"><span class="source">Fabian von Poser/Getty Images</span></span>
</figcaption>
</figure>
<p>The technology needed to track the bats and understand their migration paths is still being developed. Only a few individuals have been studied. The <a href="https://doi.org/10.1111/j.1469-7998.2008.00425.x">results</a> were nevertheless striking. The bats flew off to many places across the continent, including one <a href="https://www.movebank.org/cms/webapp?gwt_fragment=page%3Dsearch_map_linked%2CindividualIds%3D1012503941*%2Clat%3D-3.8622702237309112%2Clon%3D29.99411019999955%2Cz%3D5">all the way to South Sudan</a>. It seems that bats from several other colonies <a href="https://doi.org/10.1111/j.1469-7998.2005.00020.x">meet at Kasanka</a> during a short time of the year, probably to take advantage of the abundant fruit in the region. </p>
<h2>The counting</h2>
<p>For our new counting approach, we decided to film the bat emergence in a standard way, count the bats in each video, and then extrapolate a total number.</p>
<p>The key was collecting data from all sides of the colony. So we surrounded the bat forest with nine GoPro cameras, aimed straight upwards. These small “helmet cameras” are more typically used to film extreme sports, but were also suitable to record the dark bats flying beneath the pale evening sky. Our team of scientists and rangers would race around the park to start the cameras just before the bats started flying, take a break to marvel at the bat swarm, then return after dark to fetch the cameras, while dodging the hippos and crocodiles that share the swamp forest with the bats. </p>
<p>Back at the lodge there was just time to recharge the batteries and download the footage to prepare for filming the next day. </p>
<p>We got about 45 hours of footage over five days of filming. But we still had to actually count the bats. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Vbaia-NC0fs?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Counting bats at Kasanka. Roland Kays.</span></figcaption>
</figure>
<p>Manually counting bats in these videos was not realistic – there were just too many of them. Instead, our team developed an artificial intelligence (AI) program to recognise the bats against the evening sky, track them from frame to frame as they flew across the screen, and count them whenever they crossed the centre line. </p>
<p>The AI takes 1.25 minutes to process one minute of video. This means 40 hours of footage takes 50 hours to run on the computer. If a human took two minutes to count all the bats in a single video frame, it would take over 13 years to complete the job.</p>
<p>We checked the accuracy of the AI method by manually counting some short clips and found it was detecting 95% of the bats. </p>
<p>We then used a bit of trigonometry to figure out what portion of the total colony was flying past our cameras and extrapolated a total colony size. The highest number on one day was 987,114 bats. </p>
<p>We might not have caught the colony at peak size during our five days of counting, so we can say there are about a million bats in Kasanka at peak season in November. </p>
<p>There are <a href="https://academic.oup.com/jmammal/article/89/1/18/1021254">caves in Texas with more bats</a>, but they are much smaller. The Kasanka colony of straw coloured fruit bats is the largest (by weight) in the world by at least an order of magnitude. </p>
<h2>Future monitoring</h2>
<p>The use of cheap GoPro cameras and the innovative automatic analyses allowed us to establish an easy method (weather permitting) to count this and other colonies of animals over successive years. We hope this will allow us to identify changes in numbers to inform conservation efforts. These are important because protecting the Kasanka colony helps <a href="https://www.cms.int/">protect bats</a> from the entire sub-continent. </p>
<p>Agricultural developments are <a href="https://kasanka.com/news/reminder-to-save-kasanka-national-park/">encroaching</a> on Kasanka National Park and a wind farm is planned in the area. This could have negative effects on the numbers of bats aggregating here. Monitoring will be crucial to reveal and prevent these effects wherever the species provides <a href="https://doi.org/10.3161/150811014X683291">ecosystem services</a>.</p>
<p>Hopefully the bats will continue to darken the evening sky of Kasanka for many years to come, continuing their services as the secret gardeners of Africa.</p><img src="https://counter.theconversation.com/content/210028/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dina Dechmann receives funding from the Max Planck Institute of Animal Behavior</span></em></p><p class="fine-print"><em><span>Benjamin Koger and Roland Kays do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Monitoring and protecting the Kasanka bat colony helps protect bats from the entire sub-continent, and thus supports ecosystem services in a wide area.
Dina Dechmann, Researcher, Max Planck Institute of Animal Behavior
Benjamin Koger, Assistant Professor, School of Computing and Department of Zoology and Physiology, University of Wyoming
Roland Kays, Research Professor at NCSU and Scientist at NC Museum of Natural Sciences, North Carolina State University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/209038
2023-08-10T01:17:41Z
2023-08-10T01:17:41Z
Meet 5 marvellous mammals of the South Pacific you’ve probably never heard of
<figure><img src="https://images.theconversation.com/files/541646/original/file-20230808-21-gvt2ao.jpg?ixlib=rb-1.1.0&rect=20%2C37%2C2741%2C2086&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/waigeo-spotted-cuscus-relaxing-on-branch-1722987340">Arie de Gier, Shutterstock</a></span></figcaption></figure><p>Islands are renowned for their weird and wonderful wildlife. These isolated ecosystems present unparalleled opportunities to study evolution, and the archipelagos of the southwest Pacific are no exception. </p>
<p>This vast and diverse region encompasses 24 nations and territories. It also includes four “<a href="https://www.cepf.net/our-work/biodiversity-hotspots">biodiversity hotspots</a>”: the East Melanesian Islands, Polynesia-Micronesia, New Caledonia and New Zealand. Each contains at least 1,500 plant species found nowhere else on Earth. So their total land area may be small, but south-west Pacific islands punch well above their weight in terms of their contributions to global biodiversity.</p>
<p>Our <a href="https://www.publish.csiro.au/book/7928/">latest book</a> provides glimpses of more than 180 native mammals of the southwest Pacific, on islands that fall under the banners of Polynesia, Micronesia and Melanesia (but excluding the island of New Guinea). Indigenous species of marsupials, bats, rodents and a monotreme are among the animals found here. Not surprisingly, half of these are endemic. Many are found only on a single island or small group of islands.</p>
<p>Let’s meet five charismatic species you’ve probably never have heard of, but simply must get to know.</p>
<h2>1. Black dorcopsis or black forest wallaby (<em>Dorcopsis atrata</em>)</h2>
<p><strong>Conservation status: critically endangered</strong></p>
<p><strong>Distribution: Goodenough Island (Papua New Guinea)</strong></p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/541588/original/file-20230807-19-dbkg37.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A drawing of the black dorcopsis or black forest wallaby, side view." src="https://images.theconversation.com/files/541588/original/file-20230807-19-dbkg37.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/541588/original/file-20230807-19-dbkg37.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=420&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541588/original/file-20230807-19-dbkg37.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=420&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541588/original/file-20230807-19-dbkg37.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=420&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541588/original/file-20230807-19-dbkg37.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=528&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541588/original/file-20230807-19-dbkg37.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=528&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541588/original/file-20230807-19-dbkg37.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=528&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The black dorcopsis (<em>Dorcopsis atrata</em>) is an enigmatic wallaby from forests on the mountains of Papua New Guinea’s Goodenough Island.</span>
<span class="attribution"><span class="source">Madison Erin Mayfield</span></span>
</figcaption>
</figure>
<p>At the southeastern tip of Papua New Guinea is the gravity-defying Goodenough Island. It looms more than 2,500 metres above sea level, but it’s only about 3,900 metres wide – at the widest point. </p>
<p>Goodenough’s higher peaks are covered in rare forests. Here among the clouds is the only place you’ll find black dorcopsis.</p>
<p>Black dorcopsis often have very worn claws, suggesting they spend a great deal of time <a href="https://www.sciencedirect.com/science/article/abs/pii/S1754504811000195">digging for truffles</a> in the rocky soil. This probably plays an important role in dispersing fungi throughout their habitat. </p>
<p>Curiously, some appear to be wearing white gloves, on one or both front paws. Others do not. No one knows why. </p>
<h2>2. Waigeo cuscus (<em>Spilocuscus papuensis</em>)</h2>
<p><strong>Conservation status: vulnerable</strong></p>
<p><strong>Distribution: Waigeo (Indonesia)</strong></p>
<p>Waigeo cuscus have a remarkable coat. Irregular black splotches stand out against a background of almost pure white. In young animals these contrasting colours are subdued by the presence of blackish-grey tips to the hairs. </p>
<p>The cuscus have been photographed in the branches of fruiting fig (<em>Ficus</em> spp.) and breadfruit (<em>Artocarpus altilis</em>) trees, so they have a taste for fruit.</p>
<h2>3. Bougainville melomys (<em>Melomys bougainville</em>)</h2>
<p><strong>Conservation status: data deficient</strong></p>
<p><strong>Distribution: Bougainville (Papua New Guinea), Choiseul and Mono (Solomon Islands)</strong></p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/541590/original/file-20230807-23-tde9av.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A photo of the native rodent Bougainville melomys standing on brown leaf litter" src="https://images.theconversation.com/files/541590/original/file-20230807-23-tde9av.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/541590/original/file-20230807-23-tde9av.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541590/original/file-20230807-23-tde9av.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541590/original/file-20230807-23-tde9av.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541590/original/file-20230807-23-tde9av.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541590/original/file-20230807-23-tde9av.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541590/original/file-20230807-23-tde9av.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Bougainville melomys (<em>Melomys bougainville</em>) occurs in a wide variety of habitat on the islands of Bougainville, Choiseul and Mono.</span>
<span class="attribution"><span class="source">Stephen Richards</span></span>
</figcaption>
</figure>
<p>Pacific Island native rodents have proven vulnerable to disturbance, but thankfully Bougainville melomys seems to remain relatively common. </p>
<p>The contrast between orange fur on the head and back, and crisp white fur on the belly is rather attractive. </p>
<p>An active climber, Bougainville melomys can be found tiptoeing along thin woody vines (lianas), in fruiting trees among Bismarck common cuscuses (<em>Phalanger breviceps</em>), or scaling the trunks of wild betel nut palms (<em>Areca</em> spp.). They’ll tolerate disturbance and have been known to visit village edges to nibble on cultivated bananas.</p>
<h2>4. Lesser sheath-tailed bat (<em>Mosia nigrescens</em>)</h2>
<p><strong>Conservation status: least concern</strong></p>
<p><strong>Distribution: Widespread throughout Indonesia, Papua New Guinea and Solomon Islands</strong></p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/541591/original/file-20230807-675-za2v2r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A photo of three lesser sheath-tail bats huddled under a palm tree leaf" src="https://images.theconversation.com/files/541591/original/file-20230807-675-za2v2r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/541591/original/file-20230807-675-za2v2r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541591/original/file-20230807-675-za2v2r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541591/original/file-20230807-675-za2v2r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541591/original/file-20230807-675-za2v2r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541591/original/file-20230807-675-za2v2r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541591/original/file-20230807-675-za2v2r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Lesser sheath-tail bats (<em>Mosia nigrescens</em>) are endearing little animals that roost in ‘tents’ under palm tree leaves across parts of Melanesia.</span>
<span class="attribution"><span class="source">Stephen Richards</span></span>
</figcaption>
</figure>
<p>If you’re quiet and patient while walking through the palm-filled lowland forests of Melanesia, you might be lucky enough to spot one of the region’s smallest and most common echo locating bats. </p>
<p>Lesser sheath-tailed bats are alert little creatures with good eyesight. They rest in small groups huddled together under the cover of a palm leaf where they’re sheltered from the rain. Although watchful, they’ll stay in place if approached with caution, allowing time to view how neatly stacked they are. </p>
<p>Lesser sheath-tailed bats are among the first to emerge of an evening, leaving their palm tree tents while there is still plenty of twilight. They fly in sharp circles in the open spaces above forests and villages. Then as darkness falls, they move away to focus on other areas. </p>
<p>Later in the evening you can find them back in the same roosts, again lined up front to back, taking a breather from their busy schedule of hunting for insects on the wing.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/pacific-island-bats-are-utterly-fascinating-yet-under-threat-and-overlooked-meet-4-species-165765">Pacific Island bats are utterly fascinating, yet under threat and overlooked. Meet 4 species</a>
</strong>
</em>
</p>
<hr>
<h2>5. Palau flying-fox (<em>Pteropus pelewensis</em>)</h2>
<p><strong>Conservation status: vulnerable</strong></p>
<p><strong>Distribution: Ulithi, Yap (Federated States of Micronesia), Palau</strong></p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/541592/original/file-20230807-27645-ndrc99.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A photo of a Palau flying-fox with outstretched wings, flying over a green landscape." src="https://images.theconversation.com/files/541592/original/file-20230807-27645-ndrc99.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/541592/original/file-20230807-27645-ndrc99.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541592/original/file-20230807-27645-ndrc99.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541592/original/file-20230807-27645-ndrc99.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541592/original/file-20230807-27645-ndrc99.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541592/original/file-20230807-27645-ndrc99.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541592/original/file-20230807-27645-ndrc99.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Palau flying-fox (<em>Pteropus pelewensis</em>) has suffered from hunting and international trade.</span>
<span class="attribution"><span class="source">Thibaud Aronson</span></span>
</figcaption>
</figure>
<p>The south-west Pacific supports an incredible diversity of endemic <em>Pteropus</em> flying-foxes. Over-harvesting and international trade for human consumption pushed most of Micronesia’s flying-foxes to the brink of extinction (and in fact did send two species extinct). </p>
<p>Thankfully the introduction of restrictions under the <a href="https://cites.org/eng">Convention on International Trade in Endangered Species</a> stabilised populations of the Palau fying-fox. However, it remains <a href="https://www.iucnredlist.org/species/118093652/206768055">vulnerable</a> and threatened by habitat loss and climate change.</p>
<h2>So much to learn</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/541608/original/file-20230808-25-kenxlv.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Illustrated book cover for Mammals of the South-West Pacific" src="https://images.theconversation.com/files/541608/original/file-20230808-25-kenxlv.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/541608/original/file-20230808-25-kenxlv.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=865&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541608/original/file-20230808-25-kenxlv.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=865&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541608/original/file-20230808-25-kenxlv.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=865&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541608/original/file-20230808-25-kenxlv.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1087&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541608/original/file-20230808-25-kenxlv.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1087&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541608/original/file-20230808-25-kenxlv.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1087&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p>The species showcased here represent just a small fraction of the diversity of south-west Pacific mammals. </p>
<p>So many unique species evolved here, on discrete areas of land separated by ocean. </p>
<p>Unfortunately islands are also vulnerable to human disturbance and extinctions have <a href="https://theconversation.com/pacific-island-bats-are-utterly-fascinating-yet-under-threat-and-overlooked-meet-4-species-165765">already occurred</a> here. </p>
<p>There is still much to learn about many of these mammals. We hope <a href="https://www.publish.csiro.au/book/7928/">this book</a> will inspire more research, including how we can keep these fascinating island inhabitants thriving in a time of such great environmental change. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/humans-werent-to-blame-for-the-extinction-of-prehistoric-island-dwelling-animals-160092">Humans weren't to blame for the extinction of prehistoric island-dwelling animals</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/209038/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tyrone Lavery has received funding from the Critical Ecosystem Partnership Fund, The Australian Museum, The Field Museum of Natural History, Fondation Segre, The Australia Pacific Science Foundation, and the National Science Foundation.</span></em></p>
From the cuscus with the fancy coat, to the wallaby often sporting a single white glove, a wide variety of life evolved on island homes in the south-west Pacific.
Tyrone Lavery, The University of Melbourne
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/211074
2023-08-09T16:00:00Z
2023-08-09T16:00:00Z
Bats are avoiding solar farms and scientists aren’t sure why
<figure><img src="https://images.theconversation.com/files/541916/original/file-20230809-27-djlg20.jpg?ixlib=rb-1.1.0&rect=161%2C201%2C3932%2C2751&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The common pipistrelle.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/flying-pipistrelle-bat-pipistrellus-action-shot-1407591011">Rudmer Zwerver/Shutterstock</a></span></figcaption></figure><p>As our planet continues to warm, the need for renewable energy is becoming increasingly urgent. Almost half of the UK’s electricity now comes from renewable sources. And solar <a href="https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1165986/Energy_Trends_June_2023.pdf">accounts for one-fifth</a> of the energy capacity installed since 2019.</p>
<p>Solar farms are now a striking feature of the British landscape. But despite their growth, we’re still largely in the dark about how solar farms impact biodiversity. </p>
<p>This was the focus of a <a href="https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2664.14474">recent study</a> that I co-authored alongside colleagues from the University of Bristol. We found that bat activity is reduced at solar farms compared to neighbouring sites without solar panels. </p>
<p>This discovery is concerning. Bats are top predators of nighttime insects and are sensitive to changes in their habitats, so they are important indicators of ecosystem health. Bats also <a href="https://www.pnas.org/doi/10.1073/pnas.1505413112">provide valuable services</a> such as suppressing populations of insect pests. </p>
<p>Nonetheless, our results should not hinder the transition to renewable energy. Instead, they should help to craft strategies that not only encourage bat activity but also support the necessary expansion of clean energy sources.</p>
<figure class="align-center ">
<img alt="An aerial shot of a solar farm in south Wales." src="https://images.theconversation.com/files/541917/original/file-20230809-26-hb1q0k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/541917/original/file-20230809-26-hb1q0k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=334&fit=crop&dpr=1 600w, https://images.theconversation.com/files/541917/original/file-20230809-26-hb1q0k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=334&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/541917/original/file-20230809-26-hb1q0k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=334&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/541917/original/file-20230809-26-hb1q0k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=419&fit=crop&dpr=1 754w, https://images.theconversation.com/files/541917/original/file-20230809-26-hb1q0k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=419&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/541917/original/file-20230809-26-hb1q0k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=419&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Solar farms are now a striking feature of the British landscape.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/aerial-drone-view-solar-panels-energy-1234126882">steved_np3/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Reduced activity</h2>
<p>We measured bat activity by recording their ultrasonic echolocation calls on bat detectors. Many bat species have distinctive echolocation calls, so we could identify call sequences for each species in many cases. Some species show similar calls, so we lumped them together in species groups. </p>
<p>We placed bat detectors in a solar farm field and a similar neighbouring field without solar panels (called the control site). The fields were matched in size, land use and boundary features (such as having similar hedges) as far as possible. The only major difference was whether they contained solar panels. </p>
<p>We monitored 19 pairs of these sites, each for a week, observing bat activity within the fields’ centre and along their boundaries. Field boundaries are used by bats for navigation and feeding. </p>
<p>Six of the eight bat species or groups studied were less active in the fields with solar panels compared to the fields without them. <a href="https://www.britannica.com/animal/common-pipistrelle">Common pipistrelles</a>, which made up almost half of all bat activity, showed a decrease of 40% at the edges of solar panel fields and 86% in their centre. Other bat species or groups like <a href="https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/animals/mammals/soprano-pipistrelle-bat/">soprano pipistrelles</a>, <a href="https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/animals/mammals/noctule-bat/">noctules</a>, <a href="https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/animals/mammals/serotine-bat/">serotines</a>, <a href="https://www.northumberlandbats.org.uk/home/bat-info/northumbrian-bats/myotis-bats/">myotis bats</a> and <a href="https://www.britannica.com/animal/long-eared-bat">long-eared bats</a> also saw their activity drop. </p>
<p>Total bat activity was almost halved at the boundaries of solar panel fields compared to that of control sites. And at the centre of solar panel fields, bat activity dropped by two-thirds. </p>
<h2>Why are bats avoiding solar farms?</h2>
<p>Conflict between clean energy production and biodiversity isn’t just limited to solar farms; it’s an issue at wind farms too. Large numbers of bats are killed by colliding with the blades of wind turbines. In 2012, for example, one academic estimated that around <a href="https://wildlife.onlinelibrary.wiley.com/doi/abs/10.1002/wsb.260">888,000 bats may have been killed</a> at wind energy facilities in the United States.</p>
<p>The way solar farms affect bats is probably more indirect than this. Solar panels could, in theory, inadvertently reduce the abundance of insects by lowering the availability of the plants they feed on. We’re currently investigating whether there’s a difference in insect numbers at the solar farm sites compared to the control sites. </p>
<p>Solar panels may also reflect a bats’ echolocation calls, making insect detection more difficult. Reduced feeding success around the panels may result in fewer bats using the surrounding hedgerows for commuting, potentially explaining our findings. </p>
<p>However, bats <a href="https://www.science.org/doi/10.1126/science.aam7817">are also known</a> to collide with smooth vertical flat surfaces because they reflect echolocation calls away from bats and hence appear as empty space. Research has also found that bats sometimes <a href="https://www.nature.com/articles/ncomms1110">attempt to drink from horizontal smooth surfaces</a> because they interpret the perpendicular echoes as coming from still water. But, given the sloped orientation of solar panels, these potential direct effects may not be of primary concern.</p>
<h2>Improving habitats</h2>
<p>An important lesson from the development of wind energy is that win-win solutions exist. Ultrasonic acoustic deterrents can <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0065794">keep bats away</a> from wind turbines, while slightly reducing the wind speed that turbines become operational at (known as “cut-in speeds”) <a href="https://www.conservationevidence.com/actions/1960">has reduced bat fatality rates</a> with minimal losses to energy production. <a href="https://www.energy.gov/sites/prod/files/2015/03/f20/Operational-Mitigation-Synthesis-FINAL-REPORT-UPDATED.pdf">Research</a> suggests that increasing turbine cut-in speeds by 1.5 metres per second can reduce bat fatalities by at least 50%, with an annual loss to power output below 1%.</p>
<p>A slightly different approach could be applied to solar farms. Improving habitats by planting native trees along the boundaries of solar farm fields could potentially increase the availability of insects for bats to feed on. </p>
<p>Research that I have co-authored in recent years supports this theory. We found that the presence of landscape features such as <a href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2664.13412">tall hedgerows</a> and even <a href="https://www.sciencedirect.com/science/article/pii/S0006320722000295">isolated trees</a> on farmland has a positive effect on bat activity.</p>
<p>Carefully selecting solar sites is also important. Prior to construction, conducting environmental impact assessments could indicate the value of proposed sites to bat populations. </p>
<p>More radically, rethinking the siting of these sites so that most are placed on buildings or in areas that are rarely visited by bats, could limit their impact on bat populations. </p>
<p>Solar power is the <a href="https://www.iea.org/energy-system/renewables/solar-pv">fastest-growing source</a> of renewable energy worldwide. Its capacity is projected to overtake natural gas by 2026 and coal by 2027. Ensuring that its ecological footprint remains minimal is now particularly important. </p>
<hr>
<figure class="align-right ">
<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><strong><em>Don’t have time to read about climate change as much as you’d like?</em></strong>
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<p class="fine-print"><em><span>Gareth Jones does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
New research has found that bats avoid solar farms – but the findings should not hinder the transition to renewable energy.
Gareth Jones, Professor of Biological Sciences, University of Bristol
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/208375
2023-06-27T15:55:31Z
2023-06-27T15:55:31Z
We found coronaviruses in UK bats – so far the danger’s minimal but we need to know more about viruses that can spread to humans
<figure><img src="https://images.theconversation.com/files/534331/original/file-20230627-19-mh39br.jpg?ixlib=rb-1.1.0&rect=6%2C12%2C4238%2C2819&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/lesser-horseshoe-bat-hanging-cave-rhinolophus-2193505899">Agami Photo Agency/Shutterstock</a></span></figcaption></figure><p>Most emerging infectious diseases are caused by zoonotic pathogens – viruses and bacteria which circulate in wild and domestic animals but are also <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/mec.15463">capable of infecting humans</a>. Examples of diseases caused by zoonotic pathogens include Ebola, Middle Eastern Respiratory Syndrome (MERS) and bird flu.</p>
<p>Certain bat species act as a reservoir for <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3427567/">a range of viruses</a> that can jump to humans – for example, the closest relatives of SARS-CoV-2 (the virus that causes COVID) circulate in bats of the <em>Rhinolophus</em> genus. However, we don’t have a good understanding of the diversity of viruses circulating in bat populations in most parts of the world. We also don’t have a good idea of the number of bat viruses that could jump into humans in the future. </p>
<p>This motivated <a href="https://www.nature.com/articles/s41467-023-38717-w">new research</a>, in which we searched for RNA viruses circulating in UK bats. RNA viruses, of which SARS-CoV-2 is one, are generally considered to be the most worrying zoonotic threats. </p>
<p>We also evaluated the zoonotic potential of some of the viruses we discovered. Reassuringly, we didn’t identify any viruses currently capable of infecting humans – but one virus may need only a few mutations to do so. Continually monitoring bats and other wildlife is therefore important to protect us against future zoonotic threats.</p>
<h2>Studying UK bats</h2>
<p>Over the course of two years, we collected faecal samples from 16 bat species that breed in the UK. These were mostly from injured or grounded bats rehabilitated by the <a href="https://www.bats.org.uk">Bat Conservation Trust</a>. This strategy didn’t cause hurt or disturbance to any bat we sampled and didn’t increase contact rates between bats and humans.</p>
<p>We selected 48 faecal samples for RNA sequencing. The resulting data allowed us to identify a wide range of viruses, the majority of which infect insects found in the bats’ faeces. But we also detected a variety of viruses that infect mammals, including several coronaviruses. </p>
<p>From the faecal samples analysed, we could piece together nine complete coronavirus genomes, including two new species – of which one is closely related to the coronavirus that causes MERS. In the two species of British <em>Rhinolophus</em> bats we also found four sarbecoviruses, the same group of viruses as SARS-CoV-2.</p>
<p>Next we tested whether the coronaviruses we recovered could infect humans. To do this, we synthesised artificial sequences of the spike proteins – proteins on the surface of the virus which attach to host cells to enable cell entry – and integrated them into a “pseudovirus”. These constructs are totally safe as they cannot replicate, but still teach us about the ability of a virus to bind to and enter different cells.</p>
<p>Of all the coronaviruses we tested, one sarbecovirus was capable of entering human cells by binding the ACE2 receptor, the receptor SARS-CoV-2 uses to enter human cells. But this occurred only in human cells artificially manipulated in the lab to express an overabundance of ACE2 receptors, not at ACE2 levels found naturally in the human body.</p>
<p>This means none of the coronaviruses we found in British bats can currently infect humans, though one of the sarbecoviruses may acquire the potential to do so in the future. This sarbecovirus is probably only a few mutations away from a virus that could bind to human ACE2 receptors effectively enough to infect people.</p>
<figure class="align-center ">
<img alt="A bat flying while other bats hang in a tree." src="https://images.theconversation.com/files/534333/original/file-20230627-25-q6pfus.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534333/original/file-20230627-25-q6pfus.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=420&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534333/original/file-20230627-25-q6pfus.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=420&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534333/original/file-20230627-25-q6pfus.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=420&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534333/original/file-20230627-25-q6pfus.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=528&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534333/original/file-20230627-25-q6pfus.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=528&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534333/original/file-20230627-25-q6pfus.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=528&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Our understanding of the viruses that circulate in bats is limited.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/bat-flying-fruit-on-blue-sky-718681774">SusaImages/Shutterstock</a></span>
</figcaption>
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<p>Our study likely underestimates the true diversity of coronaviruses circulating in UK bats since we sequenced only 48 samples and not all bats are infected by all viruses at all times. Also, we could only recover viruses shed in the guts of bats, since we analysed faeces. Bats may carry other coronavirus species, for example in their lungs, which could be transmitted via aerosols.</p>
<p>Nonetheless, our research provides a blueprint for safe, non-invasive monitoring of emerging zoonotic pathogens in wildlife. </p>
<h2>Bats as reservoirs for zoonotic viruses</h2>
<p>It has been speculated that bats may <a href="https://pubmed.ncbi.nlm.nih.gov/32640245/">harbour more pathogens</a> than other mammals due to their remarkable longevity (they can live up to around 40 years in the wild), high metabolic rate necessary for flight, and unusual immune systems (for example, they tend to tolerate rather than fight off viral infections).</p>
<p>Though, the large number of zoonotic viruses carried by bats may be primarily due to their <a href="https://www.pnas.org/doi/10.1073/pnas.1919176117">high species diversity</a>. Bats comprise <a href="https://www.mammaldiversity.org/index.html">22% of the 6,649</a> known mammalian species, each carrying their own pathogens. So monitoring for viruses shouldn’t only focus on bats, but include other groups of mammals such as rodents, carnivores and ungulates (mammals with hooves).</p>
<p>Improved <a href="https://www.nature.com/articles/s41559-023-02082-0">global surveillance</a> would require four pillars spanning pathogen diversity circulating in humans, domestic animals, wildlife and the wider environment.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-its-important-to-study-coronaviruses-in-african-bats-131592">Why it's important to study coronaviruses in African bats</a>
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</em>
</p>
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<p>It’s possible COVID was caused by a zoonotic pathogen, and it’s possible it wasn’t. We don’t have conclusive evidence either way, and debate will continue. Regardless, we need programmes that allow us to flag zoonotic threats early. This could inform policies aimed at reducing humans’ exposure to concerning emerging pathogens in animals.</p>
<p>We should ideally identify pathogens with zoonotic potential before they have a chance to jump into humans and cause outbreaks. At that point, it’s probably too late. </p>
<p>But it’s not realistic to survey all wild animal populations everywhere. Given the vast diversity of viruses in circulation in wildlife, the next pressing challenge is how best to prioritise surveillance efforts.</p>
<p>Even with the best surveillance scheme imaginable, it may not be possible to prevent all future epidemics and pandemics. But improved characterisation of pathogens with zoonotic potential would still allow preemptive design and testing of vaccines and drug compounds against the most threatening zoonotic pathogens. This would greatly increase our pandemic preparedness, if and when it came to the worst.</p><img src="https://counter.theconversation.com/content/208375/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Francois Balloux receives funding from the EU Horizon 2020 programme and UKRI. </span></em></p><p class="fine-print"><em><span>Cedric Tan receives doctoral funding from Agency for Science, Technology and Research (A*STAR), Singapore. </span></em></p><p class="fine-print"><em><span>Lucy van Dorp receives funding from a UCL Excellence Fellowship.</span></em></p>
We studied 16 bat species in the UK to learn about the viruses they carry and understand the risk to humans.
Francois Balloux, Chair Professor, Computational Biology, UCL
Cedric Tan, PhD Candidate, UCL Genetics Institute, UCL
Lucy van Dorp, Senior Research Fellow, Microbial Genomics, UCL
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/203689
2023-05-02T14:05:28Z
2023-05-02T14:05:28Z
From enormous elephants to tiny shrews: how mammals shape and are shaped by Africa’s landscapes
<figure><img src="https://images.theconversation.com/files/521021/original/file-20230414-26-p86mwp.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The African elephant is the world’s largest terrestrial mammal.</span> <span class="attribution"><span class="source">Ara Monadjem</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Africa is the world’s most diverse continent for large mammals such as antelopes, zebras and elephants. The heaviest of these large mammals top the scales at over one ton, and are referred to as <a href="https://www.sciencedirect.com/science/article/pii/S2351989416300804?via%3Dihub">megafauna</a>. In fact, it’s the only continent that has not seen a mass extinction of these megafauna.</p>
<p>The continent’s megafauna community includes the world’s largest terrestrial mammal, the <a href="https://www.worldwildlife.org/species/african-elephant">African elephant</a>. Adult African bush elephants can weigh as much as 6 tons. Other giants across African continent include hippopotamuses, rhinoceroses and giraffes.</p>
<p>So, it is only in Africa that ecological interactions and dynamics can be studied as they would have been before the sudden and profound flourishing of <em>Homo sapiens</em> over the past 12 000 years; before then, megafauna would have dominated all terrestrial landscapes on all continents. A visit to Africa is, in other words, a visit to our planet’s past.</p>
<p>In my latest book, <a href="https://witspress.co.za/page/detail/African-Ark/?K=9781776147809">African Ark: Mammals, Landscape and the Ecology of a Continent</a>, I tell the story of how Africa’s mammal fauna arose. </p>
<p>It’s not just a tale of megafauna and other well-known large mammals. I pay particular attention to small mammals, such as mice, bats and shrews. That’s partly because I have been <a href="https://www.researchgate.net/profile/Ara-Monadjem">studying these creatures</a> for the past three decades.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/521018/original/file-20230414-26-d5o9p1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/521018/original/file-20230414-26-d5o9p1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=901&fit=crop&dpr=1 600w, https://images.theconversation.com/files/521018/original/file-20230414-26-d5o9p1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=901&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/521018/original/file-20230414-26-d5o9p1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=901&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/521018/original/file-20230414-26-d5o9p1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1133&fit=crop&dpr=1 754w, https://images.theconversation.com/files/521018/original/file-20230414-26-d5o9p1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1133&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/521018/original/file-20230414-26-d5o9p1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1133&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p>These animals are also generally overlooked by both scientists and the public. But without them, and the ways in which they’ve interacted with each other and with their larger cousins over tens of thousands years, Africa wouldn’t have the richly varied landscapes it does today.</p>
<p>Africa’s mammals are a global treasure that must be protected. However, the lives of local communities are inextricably linked with these mammals and the remaining natural landscapes that harbour their dwindling populations; conservation solutions will require these communities’ active participation and blessing.</p>
<p>In some areas, nature-based tourism may be a viable solution. However, much of the rest of the continent – where no tourists go – will require other, perhaps novel, approaches. What we cannot afford is the extinction of any of these beautiful creatures or the continued loss and reduction of the ecosystem services that they freely provide.</p>
<h2>Early mammal history</h2>
<p>The history of African mammals begins with an apparently unrelated group of creatures. They’re so dissimilar from each other today that taxonomists didn’t work out their true relationships until about two decades ago. These are the elephants, manatees, elephant shrews, African golden moles, hyraxes and tenrecs. Collectively they make up the super-order <em><a href="https://afrotheria.net/">Afrotheria</a></em>. </p>
<p>Today, this group accounts for only a small fraction of the mammal species on the continent. But that is only because Africa – which formed part of the prehistoric southern supercontinent of <a href="https://www.britannica.com/place/Gondwana-supercontinent">Gondwana</a> – was colonised, in stages and over millions of years, by ‘invaders’ from the northern supercontinent of <a href="https://www.britannica.com/place/Laurasia">Laurasia</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/large-mammals-shaped-the-evolution-of-humans-heres-why-it-happened-in-africa-196398">Large mammals shaped the evolution of humans: here’s why it happened in Africa</a>
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</em>
</p>
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<p>These colonists include nearly all the mammals that we normally associate with Africa, including rhinoceroses, zebras, antelopes, primates, bats and even rodents. In return, some Afrotherians, including elephants, roamed out of Africa to colonise other lands further north. </p>
<p>Other mammals, including monkeys and <a href="https://onlinelibrary.wiley.com/doi/10.1002/9781118846506.ch1">caviomorph rodents</a> (such as guinea pigs and capybaras), used Africa as a stepping stone to colonise South America, as did lemurs to colonise Madagascar.</p>
<h2>Shaped by geography</h2>
<p>The variables of physical geography have worked hand in hand with the tectonic forces of prehistory. </p>
<p>Africa is not a uniform landscape that enjoys the same climate and habitat throughout. Some parts, such as Madagascar, are not even connected to the mainland but appear as offshore islands. Terrestrial mammals typically reach islands in two ways: they either raft across the intervening sea, or cross by foot during periods of drier weather or lower sea levels that connect the islands to the mainland. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/kenyan-fossil-shows-chameleons-may-have-rafted-from-mainland-africa-to-madagascar-130814">Kenyan fossil shows chameleons may have 'rafted' from mainland Africa to Madagascar</a>
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<p>In the continent’s interior, other formidable barriers restrict and determine mammal movement. Long, deep, fast-flowing rivers, such as the Congo in central Africa, can be almost as effective a barrier as open oceans. Mountain ranges can form inland ‘islands’ that are as ecologically isolated as their ocean equivalents. </p>
<p>By providing barriers, geographical features limit the movement of animals across the landscape, thereby affecting the composition of mammal communities in different parts of the continent.</p>
<h2>Population shifts</h2>
<p>Another element that’s crucial to telling the story of Africa’s mammals is an understanding of how species and population groups are formed and fluctuate over time. </p>
<p>For example, megafauna play important roles in shaping the landscape and its plant communities. This in turn shapes many smaller animals’ habitats. Hippopotamuses in the Okavango Delta <a href="https://www.researchgate.net/figure/Components-of-the-Okavango-ecosystem-a-Hippo-trail-through-flooded-vegetation-in_fig1_247844833#:%7E:text=In%20the%20panhandle%20and%20permanent,channels%20usually%20lead%20to%20lagoons.">create and maintain open water channels</a>, which serve as critical habitat for fishes. And, by defecating in water, hippos also introduce vast amounts of organic fertiliser into this aquatic ecosystem, helping to enrich it.</p>
<p>Smaller animals, too, shape landscapes. </p>
<p>Some species of rats and mice, such as pouched mice in the genus <em>Saccostomus</em>, are granivores that feed on seeds, including those of trees responsible for bush encroachment in savannas such as the sicklebush. Colleagues and I have <a href="https://www.frontiersin.org/articles/10.3389/fevo.2021.676572/full">shown experimentally</a> that various species of mice in Eswatini actually prefer the seeds of this encroaching plant and hence can assist in controlling its spread. But these rodents require good grass cover for persistence, and hence can’t provide this ecological service in over-grazed, degraded landscapes.</p>
<p>The numbers of animals naturally fluctuate over time, typically reflecting fluctuations in food supply brought about by, for example, droughts or floods. A key determinant of these population fluctuations is also the inherent life history characteristics of a species: short-lived, fast reproducing species such as rats and mice will, by definition, experience greater fluctuations in their numbers than long-lived, slow reproducing species like elephants.</p>
<h2>Conservation</h2>
<p>My book concludes by looking at human interactions with African mammals and the need to conserve these mammals, both for their own sake and for ours. The ecosystem services provided by many mammals are crucial to a healthy environment for all species. Humans evolved in Africa and have interacted with other African mammals for millions of years here. </p>
<p>This is not true on other continents, where humans are – in geological timescales – a recent addition. It may well be that this long relationship between humans and other African mammals is the reason why, despite the losses wrought by humankind, so many large mammals persist on the continent: they have ‘learnt’ through natural selection how to survive with us.</p>
<p><em>The book was written in conjunction with wildlife journalist Mike Unwin and is published by <a href="https://witspress.co.za/page/detail/African-Ark/?K=9781776147809">Wits University Press</a>.</em></p><img src="https://counter.theconversation.com/content/203689/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ara Monadjem receives funding from Oppenheimer Generations. </span></em></p>
Africa’s mammals are a global treasure that must be protected.
Ara Monadjem, Full Professor in the Department of Biological Sciences, University of Eswatini
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/202152
2023-03-24T19:20:10Z
2023-03-24T19:20:10Z
Marsupials and other mammals separately evolved flight many times, and we are finally learning how
<figure><img src="https://images.theconversation.com/files/516876/original/file-20230322-174-mlvqar.jpg?ixlib=rb-1.1.0&rect=1818%2C745%2C3145%2C2031&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Anom Harya/Shutterstock</span></span></figcaption></figure><p><a href="https://www.goodreads.com/quotes/4324-shoot-for-the-moon-even-if-you-miss-you-ll-land">Shoot for the moon</a>. Even if you miss, you’ll land on the next tree. Many groups of mammals seem to have taken this evolutionary advice to heart. According to our <a href="http://dx.doi.org/10.1126/sciadv.ade7511">newly published paper in Science Advances</a>, unrelated animals may even have used the same blueprints for building their “wings”.</p>
<p>While birds are the undisputed champions of the sky, <a href="https://doi.org/10.1016/j.cub.2015.08.003">having mastered flight during the Jurassic</a>, mammals have actually evolved flight more often than birds. In fact, as many as seven different groups of mammals living today have <a href="https://doi.org/10.1111/evo.14094">taken to the air independently of each other</a>.</p>
<p>These evolutionary experiments happened in animals scattered all across the mammalian family tree – including flying squirrels, marsupial possums and the colugo (cousin of the primates). But they all have something in common. It’s a special skin structure between their limbs called a patagium, or flight membrane. </p>
<p>The fact these similar structures have arisen so many times (a process called <a href="https://doi.org/10.1098/rstb.2019.0102">convergent evolution</a>) hints that the genetic underpinnings of patagia might predate flight. Indeed, they could be shared by all mammals, even those living on the ground. </p>
<p>If this is true, studying patagia can help us to better understand the incredible adaptability of mammals. We might also discover previously unknown aspects of human genetics.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/516879/original/file-20230322-18-nf6b9f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A cute grey and cream striped animal on a tree branch with distinctive skin folds visible on its side" src="https://images.theconversation.com/files/516879/original/file-20230322-18-nf6b9f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/516879/original/file-20230322-18-nf6b9f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=498&fit=crop&dpr=1 600w, https://images.theconversation.com/files/516879/original/file-20230322-18-nf6b9f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=498&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/516879/original/file-20230322-18-nf6b9f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=498&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/516879/original/file-20230322-18-nf6b9f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=626&fit=crop&dpr=1 754w, https://images.theconversation.com/files/516879/original/file-20230322-18-nf6b9f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=626&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/516879/original/file-20230322-18-nf6b9f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=626&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sugar gliders are one of several mammals that have independently evolved the ability to fly through the air.</span>
<span class="attribution"><span class="source">apiguide/Shutterstock</span></span>
</figcaption>
</figure>
<h2>A deceptively simple membrane</h2>
<p>Despite being seemingly simple skin structures, patagia contain several tissues, including hair, a rich array of <a href="https://doi.org/10.1073/pnas.1018740108">touch-sensitive neurons</a>, <a href="https://doi.org/10.1071/ZO9870101"></a><a href="https://doi.org/10.1038/ncomms2298">connective tissue and even thin sheets of muscle</a>. But in the earliest stages of formation, these membranes are dominated by the two main layers of the skin: the inner dermis and outer epidermis.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/516542/original/file-20230321-22-8mhzbz.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A pink baby animal looking much like an embryo with a red arrow pointing at a thin membrane it its armpit" src="https://images.theconversation.com/files/516542/original/file-20230321-22-8mhzbz.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/516542/original/file-20230321-22-8mhzbz.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=780&fit=crop&dpr=1 600w, https://images.theconversation.com/files/516542/original/file-20230321-22-8mhzbz.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=780&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/516542/original/file-20230321-22-8mhzbz.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=780&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/516542/original/file-20230321-22-8mhzbz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=980&fit=crop&dpr=1 754w, https://images.theconversation.com/files/516542/original/file-20230321-22-8mhzbz.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=980&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/516542/original/file-20230321-22-8mhzbz.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=980&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The patagium in sugar gliders (red arrow) forms after birth when the newborn, or joey, is in its marsupial mother’s pouch.</span>
<span class="attribution"><span class="source">Charles Feigin</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>At first, they hardly differ from neighbouring skin. But at some point, the skin on the animal’s sides starts to rapidly change, or differentiate. The dermis undergoes a process called condensation, where cells bunch up and the tissue becomes very dense. Meanwhile, the epidermis thickens in a process called hyperplasia.</p>
<p>In some mammals, this differentiation happens when they are still an embryo in the uterus. Incredibly though, in our main model species – the marsupial sugar glider (<em><a href="https://australian.museum/learn/animals/mammals/sugar-glider/">Petaurus breviceps</a></em>) – this process begins after birth, while they are in the mother’s pouch. This provides us with an incredible window into patagium formation.</p>
<p>Starting with the sugar glider, we examined the behaviours of thousands of genes active during the early development of the patagium, to try and figure out how this chain of events is kicked off.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-rare-discovery-we-found-the-sugar-glider-is-actually-three-species-but-one-is-disappearing-fast-142807">A rare discovery: we found the sugar glider is actually three species, but one is disappearing fast</a>
</strong>
</em>
</p>
<hr>
<h2>From gliders to bats</h2>
<p>We discovered that levels of a gene called Wnt5a are strongly correlated with the onset of those early skin changes – condensation and hyperplasia. Through a series of experiments involving cultured skin tissues and genetically engineered laboratory mice, we showed that adding extra Wnt5a was all it took to drive both of these early hallmarks of patagium formation.</p>
<p>Interestingly, when we extended our work to bats, we found extremely similar patterns of Wnt5a activity in their developing lateral patagia to that in sugar gliders. This was surprising, since bats (placental mammals) last shared a common ancestor with the marsupial sugar glider around 160 million years ago.</p>
<p>Perhaps even more remarkably, we found a nearly identical pattern in the outer ear (or pinna) of lab mice. The pinna is a nearly universal trait among mammals, including innumerable species with no flying ancestry. </p>
<figure class="align-right ">
<img alt="A dark bat with an upturned nose with its wings spread out" src="https://images.theconversation.com/files/516878/original/file-20230322-22-kkqk3x.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/516878/original/file-20230322-22-kkqk3x.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=527&fit=crop&dpr=1 600w, https://images.theconversation.com/files/516878/original/file-20230322-22-kkqk3x.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=527&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/516878/original/file-20230322-22-kkqk3x.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=527&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/516878/original/file-20230322-22-kkqk3x.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=663&fit=crop&dpr=1 754w, https://images.theconversation.com/files/516878/original/file-20230322-22-kkqk3x.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=663&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/516878/original/file-20230322-22-kkqk3x.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=663&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Seba’s short-tailed bat has a lateral patagium (connected to the flank of the body) activated by Wnt5a.</span>
<span class="attribution"><a class="source" href="https://www.inaturalist.org/observations/110870566">Irineu Cunha/iNaturalist</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<h2>A molecular toolkit</h2>
<p>Together, these results suggest something profound. Wnt5a’s role in ushering in the skin changes needed for a patagium likely evolved long before the first mammal ever took to the air.</p>
<p>Originally, the gene had nothing to do with flight, instead contributing to the development of seemingly unrelated traits. But because of shared ancestry, most living mammals today inherited this Wnt5a-driven program. When species like gliders and bats started on their separate journeys into the air, they did so with a common “molecular toolkit”.</p>
<p>Not only that, but this same toolkit is likely present in humans and working in ways we don’t fully understand yet.</p>
<p>There are definite limits to our recent work. First, we haven’t made a flying mouse. This may sound like a joke, but demonstrates we still don’t fully understand how a region of dense, thick skin becomes a thin and wide flight membrane. Many more genes with unknown roles are bound to be involved.</p>
<p>Second, while we’ve shown a cause-and-effect relationship between Wnt5a and patagium skin differentiation, we don’t know precisely how Wnt5a does it. Moving forward, we hope to fill in these gaps by broadening the horizons of our cross-species comparisons and by conducting more in-depth molecular studies on patagium formation in sugar gliders.</p>
<p>For now though, our study presents an exciting new view of flight in mammals. We may not be the strongest fliers, but trying is in our DNA.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/mysterious-poles-make-road-crossing-easier-for-high-flying-mammals-11323">Mysterious poles make road crossing easier for high flying mammals</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/202152/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Charles Feigin has received fellowship funding from the National Institutes of Health National Institute of General Medical Sciences </span></em></p>
Mammals have evolved flight more often than birds. By studying the genes of the sugar glider, biologists have found a ‘molecular toolkit’ for flight membranes that’s been in us all along.
Charles Feigin, Postdoctoral Fellow in Genomics and Evolution, The University of Melbourne
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/200486
2023-03-13T12:26:20Z
2023-03-13T12:26:20Z
Marburg virus outbreaks are increasing in frequency and geographic spread – three virologists explain
<figure><img src="https://images.theconversation.com/files/514041/original/file-20230307-20-6vacw1.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2100%2C2190&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Marburg virus spreads through close contact with infected body fluids.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/QPbCNb">NIAID/flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>The World Health Organization confirmed an <a href="https://www.who.int/emergencies/disease-outbreak-news/item/2023-DON444">outbreak of the deadly Marburg virus disease</a> in the central African country of Equatorial Guinea on Feb. 13, 2023. To date, there have been <a href="https://www.rfi.fr/en/international-news/20230228-death-toll-in-e-guinea-marburg-outbreak-rises-to-11">11 deaths suspected to be caused by the virus</a>, with one case confirmed. Authorities are currently monitoring 48 contacts, four of whom have developed symptoms and three of whom are hospitalized as of publication. The WHO and the U.S. Centers for Disease Control and Prevention are assisting Equatorial Guinea in its efforts to stop the spread of the outbreak.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/514050/original/file-20230307-16-7oenhk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Microscopy image of Marburg virus particles" src="https://images.theconversation.com/files/514050/original/file-20230307-16-7oenhk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/514050/original/file-20230307-16-7oenhk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=838&fit=crop&dpr=1 600w, https://images.theconversation.com/files/514050/original/file-20230307-16-7oenhk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=838&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/514050/original/file-20230307-16-7oenhk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=838&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/514050/original/file-20230307-16-7oenhk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1053&fit=crop&dpr=1 754w, https://images.theconversation.com/files/514050/original/file-20230307-16-7oenhk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1053&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/514050/original/file-20230307-16-7oenhk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1053&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Marburg virus is structurally similar to the Ebola virus.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/marburg-virus-is-a-hemorrhagic-fever-virus-first-described-news-photo/1035562466">Photo12/Universal Images Group via Getty Images</a></span>
</figcaption>
</figure>
<p><a href="https://doi.org/10.3390/v4101878">Marburg virus</a> and the <a href="https://doi.org/10.12688/f1000research.17573.1">closely related</a> Ebola virus belong to the <a href="https://doi.org/10.1016/j.jmb.2019.06.029">filovirus family</a> and are <a href="https://doi.org/10.1007/82_2017_16">structurally</a> <a href="https://doi.org/10.3201%2Feid1008.040350">similar</a>. Both viruses cause severe disease and death in people, with fatality rates ranging from 22% to 90% <a href="https://www.cdc.gov/vhf/ebola/index.html">depending on</a> <a href="https://www.cdc.gov/vhf/marburg/index.html">the outbreak</a>. Patients infected by these viruses exhibit a <a href="https://doi.org/10.1016/j.ijid.2020.07.042">wide range of similar symptoms</a>, including fever, body aches, severe gastrointestinal symptoms like diarrhea and vomiting, lethargy and sometimes bleeding.</p>
<p>We are <a href="https://scholar.google.com/citations?user=rUT_g04AAAAJ&hl=en&oi=ao">virologists</a> <a href="https://scholar.google.com/citations?hl=en&user=j9jTdBsAAAAJ">who</a> <a href="https://scholar.google.com/citations?user=PdTPtc8AAAAJ&hl=en&oi=ao">study</a> Marburg, Ebola and related viruses. <a href="https://www.bu.edu/muhlbergerlab/">Our laboratory</a> has a long-standing interest in researching the underlying mechanisms of how these viruses cause disease in people. Learning more about how Marburg virus is transmitted from animals to humans and how it spreads between people is essential to preventing and limiting future outbreaks. </p>
<h2>Marburg virus disease</h2>
<p>Marburg virus spreads between people by close contact only after they show symptoms. It is transmitted through <a href="https://doi.org/10.1016/j.ijid.2020.07.042">infected body fluids</a> such as blood, and is not airborne. Contact tracing is a potent tool to combat outbreaks. The incubation time, or time between infection and the onset of symptoms, ranges from two to 21 days and typically falls between five and 10 days. This means that contacts must be observed for extended periods for potential symptoms. </p>
<p>Marburg virus <a href="https://doi.org/10.1093/infdis/jir299">cannot be detected before patients are symptomatic</a>. One major cause of the spread of Marbug virus disease is <a href="https://doi.org/10.3201/eid0912.030355">postmortem transmission</a> due to traditional burial procedures, where family and friends typically have direct skin-to-skin contact with people who have died from the disease.</p>
<p>There are currently no approved <a href="https://doi.org/10.1016/j.ijid.2020.07.042">treatments</a> or <a href="https://doi.org/10.1016/j.vaccine.2020.11.042">vaccines</a> against Marburg virus disease. The most advanced vaccine candidates in development use strategies that <a href="https://doi.org/10.1016/j.ebiom.2023.104463">have been shown</a> <a href="https://doi.org/10.3390/vaccines10101582">to be effective</a> at <a href="https://doi.org/10.1126/scitranslmed.abq6364">protecting against</a> <a href="https://doi.org/10.1016/S0140-6736(22)02400-X">Ebola virus disease</a>. </p>
<p>Without effective treatments or vaccines, Marburg virus <a href="https://doi.org/10.1086/520548">outbreak control</a> primarily relies on contact tracing, sample testing, patient contact monitoring, quarantines and attempts to limit or modify high-risk activities such as <a href="https://doi.org/10.1086/520544">traditional funeral practices</a>.</p>
<h2>What causes Marburg virus outbreaks?</h2>
<p>Marburg virus outbreaks have an unusual history. </p>
<p>The <a href="https://doi.org/10.1086/520551">first recorded outbreak</a> of Marburg virus disease occurred in Europe. In 1967, laboratory workers in Marburg and Frankfurt in Germany, as well as in Belgrade, Yugoslavia (now Serbia) were <a href="https://doi.org/10.1136/pgmj.49.574.542">infected with a previously unknown pathogen</a> after handling infected monkeys that had been imported from Uganda. This outbreak led to the <a href="https://doi.org/10.1086/520551">discovery of the Marburg virus</a>.</p>
<p>Identifying the virus took only three months, which, at the time, was incredibly fast considering the available research tools. Despite receiving intensive care, <a href="https://doi.org/10.1086/520551">seven of the 32 patients died</a>. This case fatality rate of 22% was relatively low compared to subsequent Marburg virus outbreaks in Africa, which have had a <a href="https://www.cdc.gov/vhf/marburg/outbreaks/chronology.html">cumulative case fatality rate of 86%</a>. It remains unclear if these differences in lethality are due to variability in patient care options or other factors such as distinct viral strains.</p>
<p>Subsequent Marburg virus disease outbreaks occurred in Uganda and Kenya, as well as the Democratic Republic of the Congo and Angola in Central Africa. In addition to the current outbreak in Equatorial Guinea, recent Marburg virus cases in the West African countries of Guinea in 2021 and Ghana in 2022 highlight that the Marburg virus is <a href="https://www.cdc.gov/vhf/marburg/outbreaks/chronology.html">not confined to Central Africa</a>.</p>
<p>Strong evidence shows that the <a href="https://doi.org/10.1371/journal.ppat.1000536">Egyptian fruit bat</a>, a natural animal reservoir of Marburg virus, might play an important role in spreading the virus to people. The location of all Marburg virus outbreaks coincides with the <a href="https://www.iucnredlist.org/species/29730/22043105">natural range of these bats</a>. The large area of Marburg virus outbreaks is unsurprising, given the <a href="https://doi.org/10.3390/v4101878">ecology of the virus</a>. However, the mechanisms of zoonotic, or animal-to-human, spread of Marburg virus still remain poorly understood.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/514042/original/file-20230307-16-m3dkhs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Researchers approaching Bat Cave in Queen Elizabeth National Park" src="https://images.theconversation.com/files/514042/original/file-20230307-16-m3dkhs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/514042/original/file-20230307-16-m3dkhs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=403&fit=crop&dpr=1 600w, https://images.theconversation.com/files/514042/original/file-20230307-16-m3dkhs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=403&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/514042/original/file-20230307-16-m3dkhs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=403&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/514042/original/file-20230307-16-m3dkhs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=506&fit=crop&dpr=1 754w, https://images.theconversation.com/files/514042/original/file-20230307-16-m3dkhs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=506&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/514042/original/file-20230307-16-m3dkhs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=506&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A number of Marburg virus outbreaks are linked to human activity in caves where Egyptian fruit bats are known to roost.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/jennifer-mcquiston-jonathan-towner-and-brian-amman-approach-news-photo/1073367830">Bonnie Jo Mount/The Washington Post via Getty Images</a></span>
</figcaption>
</figure>
<p>The origin of a number of Marburg virus disease outbreaks is closely linked to human activity in caves where Egyptian fruit bats roost. More than half of the cases in a 1998 outbreak in the northeastern Democratic Republic of the Congo were among <a href="https://doi.org/10.1056/NEJMoa051465">gold miners who had worked in Goroumbwa Mine</a>. Intriguingly, the end of the nearly two-year outbreak coincided with the flooding of the cave and the disappearance of the bats in the same month.</p>
<p>Similarly, in 2007, four men who <a href="https://doi.org/10.1093/infdis/jir312">worked in a gold and lead mine</a> in Uganda where thousands of bats were known to roost became infected with Marburg virus. In 2008, two tourists were infected with the virus after visiting <a href="https://www.cdc.gov/cdctv/diseaseandconditions/outbreaks/uganda-python-cave.html">Python Cave</a> in the Maramagambo Forest in Uganda. Both developed severe symptoms after returning to their home countries – the <a href="https://doi.org/10.3201%2Feid1508.090051">woman from the Netherlands died</a> and the <a href="https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5849a2.htm">woman from the United States survived</a>.</p>
<p>The <a href="https://www.iucnredlist.org/species/29730/22043105">geographic range of Egyptian fruit bats</a> extends to large portions of sub-Saharan Africa and the Nile River Delta, as well as portions of the Middle East. There is potential for <a href="https://theconversation.com/what-is-spillover-bird-flu-outbreak-underscores-need-for-early-detection-to-prevent-the-next-big-pandemic-200494">zoonotic spillover events</a>, to occur in any of these regions.</p>
<h2>More frequent outbreaks</h2>
<p>Although Marburg virus disease outbreaks have historically been sporadic, their <a href="https://www.cdc.gov/vhf/marburg/outbreaks/chronology.html">frequency has been increasing</a> in recent years. </p>
<p>The increasing emergence and reemergence of zoonotic viruses, including filoviruses (such as <a href="https://www.cdc.gov/vhf/ebola/index.html">Ebola</a>, <a href="https://www.cdc.gov/mmwr/volumes/71/wr/mm7145a5.htm">Sudan</a> and <a href="https://www.cdc.gov/vhf/marburg/index.html">Marburg</a> viruses), coronaviruses (which cause <a href="https://www.cdc.gov/sars/index.html">SARS</a>, <a href="https://www.cdc.gov/coronavirus/mers/index.html">MERS</a> and <a href="https://www.cdc.gov/coronavirus/2019-ncov/index.html">COVID-19</a>), henipaviruses (such as <a href="https://www.cdc.gov/vhf/nipah/index.html">Nipah</a> and <a href="https://www.cdc.gov/vhf/hendra/index.html">Hendra</a> viruses) and <a href="https://www.cdc.gov/poxvirus/mpox/index.html">Mpox</a> appear to be influenced by both <a href="https://doi.org/10.1038/s41586-022-05506-2">human encroachment</a> on previously undisturbed animal habitats and alterations to wildlife habitat ranges <a href="https://doi.org/10.1038/s41586-022-04788-w">due to climate change</a>. </p>
<p>Most Marburg virus outbreaks have occurred in remote areas, which has helped to contain the spread of the disease. However, the large geographic distribution of Egyptian fruit bats that harbor the virus raises concerns that future Marburg virus disease outbreaks could happen in new locations and spread to more densely populated areas, as seen by the devastating <a href="https://doi.org/10.1007/82_2017_69">Ebola virus outbreak in 2014 in West Africa</a>, where <a href="https://www.cdc.gov/vhf/ebola/history/2014-2016-outbreak/index.html">over 11,300 people died</a>.</p><img src="https://counter.theconversation.com/content/200486/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Elke Mühlberger receives funding from NIH/NIAID, the Bill and Melinda Gates Foundation, the Howard Hughes
Medical Institute (as coinvestigator on Emerging Pathogens Initiative project). </span></em></p><p class="fine-print"><em><span>Adam Hume and Judith Olejnik do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
The Marburg virus, a close cousin of Ebola, currently has no approved treatments or vaccines to protect against it.
Adam Hume, Research Assistant Professor of Microbiology, Boston University
Elke Mühlberger, Professor of Microbiology, Boston University
Judith Olejnik, Senior Research Scientist, Boston University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/192810
2023-01-31T13:15:48Z
2023-01-31T13:15:48Z
Mini creatures with mighty voices know their audience and focus on a single frequency
<figure><img src="https://images.theconversation.com/files/506448/original/file-20230125-20-qo2fa8.jpg?ixlib=rb-1.1.0&rect=799%2C1210%2C3639%2C1815&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The coquí frog, *Eleutherodactylus coqui*, is loud enough to wake people at night.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/atardecerboricua/6412552985/in/photolist-nqd2wM-siBCx-9U7tfN-3dc6jS-nqYftj-2obkoYQ-nsGGeX-2ob6cY8-3dc5gN-2obhqNm-2ob784C-4wSjbL-MJzjq-8FRYs3-8FNNcF-8FNMP8-8FNLHa-K2daUb-aLE1An-D9pPx5-bvssQd-dK5Cia-dKb61y-dKb6nj-CD8QSt-K2daXs">Éktor/flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>In the cloud forests of South America, amid the constant cacophony of bird and insect noise, a deafening blare pierces through the background from time to time. Belonging to the loudest known bird, the white bellbird, <em>Procnias albus</em>, this sound would be painful to humans listening nearby and capable of causing <a href="https://www.cdc.gov/nceh/hearing_loss/what_noises_cause_hearing_loss.html">immediate hearing damage from about a yard away</a>.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/dvK-DujvpSY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Listen to the world’s loudest bird call.</span></figcaption>
</figure>
<p><a href="https://doi.org/10.1016/j.cub.2019.09.028">Made exclusively by males serenading females</a>, these vocalizations can reach peak levels of more than 120 decibels on the sound pressure level scale (dB SPL), which is equivalent to a <a href="https://planenerd.com/decibels-of-a-jet-engine/">jet aircraft taking off from 100 yards away</a>. <a href="https://doi.org/10.1016/j.cub.2019.09.028">The female bellbird listens some distance from the male</a>, presumably trading off being close enough to assess his quality as a mate without damaging her ears. </p>
<p>I study the <a href="https://scholar.google.com/citations?hl=en&user=IekcMzwAAAAJ">hearing ability of animals and the sounds they make</a> to communicate. A great number of calls exist throughout the animal kingdom – and many are used to attract mates or defend territories. Evolution has favored those able to make sounds efficiently. The <a href="https://doi.org/10.1006/anbe.2003.2093">louder and more focused</a> the energy in the call and the <a href="https://doi.org/10.1007/978-1-4612-1182-2_7">closer in pitch</a> it is to the intended listener’s optimal hearing range, the farther away a potential mate or rival will hear it. </p>
<p>Many large mammals, such as singing whales, roaring lions and rumbling elephants, <a href="https://doi.org/10.1007/BF00299740">produce loud low-pitched sounds</a> that travel especially well through most habitats. Because of their petite physical size, small animals are not capable of making these far-reaching low-frequency sounds. </p>
<p>As a workaround, a number of small creatures have found ingenious ways to deliver their messages loudly, despite their size.</p>
<h2>Ultrasonic calls</h2>
<p>Human ears are most sensitive to the <a href="https://www.researchgate.net/figure/Audiogram-showing-the-average-human-threshold-for-pure-tones-obtained-in-a-sound-field_fig2_6597029">highest notes on a piano</a> – about 4 kHz – a unit of measurement that is the physical metric for pitch. Anything above 20 kHz is considered ultrasonic – undetectable to human ears. But such sounds are not undetectable to all ears.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/506443/original/file-20230125-7959-o0r30p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Close-up photo of a bat's head showing large and elaborately ridged ears." src="https://images.theconversation.com/files/506443/original/file-20230125-7959-o0r30p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506443/original/file-20230125-7959-o0r30p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506443/original/file-20230125-7959-o0r30p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506443/original/file-20230125-7959-o0r30p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506443/original/file-20230125-7959-o0r30p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506443/original/file-20230125-7959-o0r30p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506443/original/file-20230125-7959-o0r30p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The greater bulldog bat’s ear is engineered for ultrasonic hearing.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/thomascuypers/49186734333/in/photolist-e5mhwn-2hWsStF-2hWvqig-XMHZf9-XMHZaE-XMHZ8q-qPdXtS">Thomas Cuypers/flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>For example, the greater bulldog bat, <em>Noctilio leporinus</em>, can produce <a href="https://doi.org/10.1007/BF00184422">ultrasonic echolocation calls between 30 and 60 kHz</a> when hunting prey and maneuvering during flight. These calls can also get <a href="https://doi.org/10.1371/journal.pone.0002036">incredibly loud – above 140 dB SPL</a>.</p>
<p>Many other small mammals, including other bats, and even some primates such as tiny tarsiers, produce <a href="https://doi.org/10.1098/rsbl.2011.1149">loud ultrasonic sounds humans can’t perceive</a>. In part, these sounds can reach such volumes because their acoustic power is concentrated in a pure tone or single frequency. </p>
<h2>Creating speakers</h2>
<p>Insects are some of the smallest animals to produce loud sounds, chief among them the cicadas and the orthopterans, which include katydids, grasshoppers and crickets. </p>
<p>In North America, the robust conehead, <em>Neoconocephalus robustus</em>, a type of katydid, <a href="https://doi.org/10.1016/0022-1910(77)90127-5">regularly surpasses 105 dB SPL</a>. These calls are produced to attract mates and, like many such calls, are competing against a clamor of comparable sounds from similar species. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/506436/original/file-20230125-16-uec92.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Close-up photo of an insect on a leaf with a hole chewed into it roughly the size of the insect's wings." src="https://images.theconversation.com/files/506436/original/file-20230125-16-uec92.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506436/original/file-20230125-16-uec92.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=391&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506436/original/file-20230125-16-uec92.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=391&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506436/original/file-20230125-16-uec92.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=391&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506436/original/file-20230125-16-uec92.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=491&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506436/original/file-20230125-16-uec92.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=491&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506436/original/file-20230125-16-uec92.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=491&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A two-spotted tree cricket, <em>Neoxabea bipunctata</em>, chews a hole just the right size for its fore wings. It then ‘sings’ by poking the wings through the hole and rubbing them together.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/pcoin/4027378063">Patrick Coin/flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>Some insects go one step further, amplifying their sounds by building the functional equivalent of audio speakers. Some tree crickets chew holes in leaves, place their vibrating wings in the opening and <a href="https://doi.org/10.1038/255142a0">use the surrounding leaf as a baffle</a> to prevent the loss of sound energy around the edges of their wings. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/506457/original/file-20230125-24-w5uxcx.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Drawing depicting twin burrows joining below ground in a chamber inhabited by a cricket." src="https://images.theconversation.com/files/506457/original/file-20230125-24-w5uxcx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506457/original/file-20230125-24-w5uxcx.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=510&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506457/original/file-20230125-24-w5uxcx.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=510&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506457/original/file-20230125-24-w5uxcx.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=510&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506457/original/file-20230125-24-w5uxcx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=641&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506457/original/file-20230125-24-w5uxcx.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=641&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506457/original/file-20230125-24-w5uxcx.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=641&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The male mole cricket sings from his specially designed burrow, which amplifies sound like a horn.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Mole_cricket#/media/File:Mole_cricket_burrow.png">Ian Alexander, new drawing based on Bennet-Clark, 1970 with public domain insect from Lydekker 1879</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Mole crickets, <em>Gryllotalpa vineae</em>, go even further by <a href="https://doi.org/10.1080/09524622.1996.9753321">constructing a burrow that acts like a wind instrument</a>, creating a cavity of vibrating air that amplifies the sound energy they produce. <a href="https://doi.org/10.1242/jeb.128.1.383">These crickets’ songs can travel almost half a mile</a> (0.8 kilometer).</p>
<h2>Irksome invaders</h2>
<p>The <a href="https://welcome.topuertorico.org/coqui.shtml">official mascot of Puerto Rico</a> is a 1-to-2-inch (2-5-centimeter) frog called the coquí, <em>Eleutherodactylus coqui</em>, whose call is a combination of two pure tones – “ko” and “kee,” from which it gets its name. At 114-120 dB SPL, the frog’s calls are so loud they actually must <a href="https://doi.org/10.1121/1.402844">protect their own hearing when vocalizing</a>, by increasing the air pressure inside their middle ear.</p>
<p>Unfortunately, in the past few decades humans have accidentally <a href="https://www.pbs.org/newshour/science/grab-earplugs-invasive-coqui-frogs-gain-foothold-california">introduced the coquí</a> to a number of areas outside their native range, in particular the Hawaiian islands, <a href="https://www.oahuisc.org/coqui-frog/">where they have no natural predators</a> and <a href="https://www.biisc.org/pest/coqui/">have become invasive pests</a>. Since coquí calls are within an octave of humans’ best hearing – and they’re nocturnal – many Hawaiians suffer <a href="https://www.nps.gov/articles/coqui.htm">sleep disruptions because of the tiny frogs</a>.</p>
<p>So even if you’re small, it’s not impossible to make yourself heard. You just have to blast all your acoustic energy in a single frequency, and hit the sweet spot of your audience’s hearing.</p><img src="https://counter.theconversation.com/content/192810/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bernard Lohr has received funding from the National Institute on Deafness and Other Communication Disorders and the U. S. Fish and Wildlife Service. </span></em></p>
From insects to birds to bats to frogs, these little loudmouths have found ingenious ways to deliver their messages at high volume.
Bernard Lohr, Associate Professor of Biological Sciences, University of Maryland, Baltimore County
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/195593
2022-12-30T08:27:09Z
2022-12-30T08:27:09Z
Five human technologies inspired by nature – from velcro to racing cars
<figure><img src="https://images.theconversation.com/files/500467/original/file-20221212-114007-p3m533.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3055%2C2024&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Many of humanity's innovations have taken inspiration from the natural world.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/great-white-shark-carcharodon-carcharias-surface-1706225779">Alessandro De Maddalena/Shutterstock</a></span></figcaption></figure><p>Nature has, over millions of years, evolved solutions to adapt to an array of challenges. As the challenges facing humanity become more complex, we are seeing inspiration being increasingly drawn from nature. </p>
<p>Taking biological processes and applying them to technological and design problems is called <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/bioinspiration">bioinspiration</a>. This is a fast-growing field, and our ability to copy nature is becoming more sophisticated. Here are five striking examples where nature has guided human innovation – and in some cases, could lead to even more exciting breakthroughs. </p>
<h2>1. Navigation</h2>
<p>Using <a href="https://www.nps.gov/subjects/bats/echolocation.htm">echolocation</a>, bats are able to fly in <a href="https://www.sciencedirect.com/science/article/pii/B9780128093245210316">complete darkness</a>. They emit sound and ultrasound waves, then monitor the time and magnitude of these waves’ reflections to create <a href="https://www.sciencedirect.com/science/article/abs/pii/S1071581907000833">three-dimensional spatial maps</a> of their surroundings. </p>
<p>The sensors that identify obstacles when reversing in many modern cars are <a href="https://www.techbriefs.com/component/content/article/tb/pub/features/articles/36374">inspired</a> by bat navigation. The direction and distance of an obstacle is calculated by emitting ultrasound waves which reflect off objects in a car’s path.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/498452/original/file-20221201-6347-cjueta.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/498452/original/file-20221201-6347-cjueta.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=429&fit=crop&dpr=1 600w, https://images.theconversation.com/files/498452/original/file-20221201-6347-cjueta.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=429&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/498452/original/file-20221201-6347-cjueta.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=429&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/498452/original/file-20221201-6347-cjueta.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=539&fit=crop&dpr=1 754w, https://images.theconversation.com/files/498452/original/file-20221201-6347-cjueta.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=539&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/498452/original/file-20221201-6347-cjueta.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=539&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The echolocation concept has been adopted by many technologies in modern life, Amin Al-Habaibeh, Author provided.</span>
</figcaption>
</figure>
<p>Sensory navigation technologies have also been <a href="https://www.sciencedirect.com/science/article/pii/S1877050915031312">proposed</a> to improve the safety of those with restricted vision. Ultrasound sensors installed on the human body would offer sound-based feedback of a person’s surroundings. This would allow them to move more freely by eliminating the threat of obstacles.</p>
<h2>2. Construction equipment</h2>
<p>Woodpeckers <a href="https://www.batzner.com/resources/blog-posts/why-woodpeckers-peck-and-prevent-them-from-pecking-your-house/#:%7E:text=They%20peck%20at%20wood%20to,is%20attached%20to%20a%20building.">knock</a> on the hard surface of trees to forage for food, build nests and attract a mate. Construction tools, such as handheld hydraulic and pneumatic hammers, mimic the <a href="https://apologeticspress.org/the-jackhammer-in-your-backyard-2315/">vibrating bill of a woodpecker</a> using a frequency roughly equivalent to a woodpecker’s hammering (<a href="https://www.sciencedirect.com/science/article/abs/pii/S1672652914600457">20 to 25 Hz</a>). </p>
<figure class="align-center ">
<img alt="A woodpecker feeding chicks in its nest in a hole of a tree." src="https://images.theconversation.com/files/499263/original/file-20221206-25-zf8fph.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/499263/original/file-20221206-25-zf8fph.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/499263/original/file-20221206-25-zf8fph.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/499263/original/file-20221206-25-zf8fph.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/499263/original/file-20221206-25-zf8fph.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/499263/original/file-20221206-25-zf8fph.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/499263/original/file-20221206-25-zf8fph.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Woodpeckers knock on the hard surface of trees to forage for food, build nests and attract a mate.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/great-spotted-woodpecker-dendrocopos-major-perched-2060062277">Vaclav Matous/Shutterstock</a></span>
</figcaption>
</figure>
<p>But the vibration of these power tools can damage the hands of construction workers. This can, in some cases, cause <a href="https://www.hse.gov.uk/mvr/topics/vibration.htm">vibration white finger</a>, a condition where sufferers experience permanent numbness and pain in their hands and arms. </p>
<p><a href="https://www.sciencedirect.com/science/article/abs/pii/S0960982222009964">Research</a> is now studying how woodpeckers protect their brains from the impact of repeated drilling. One <a href="https://www.sciencedirect.com/science/article/abs/pii/S175161611830688X?via%3Dihub">study</a> found that woodpeckers have several impact-absorbing adaptions that other birds do not have. </p>
<p>Their skull is adapted to be tough and hard, and their tongue wraps around the back of the skull and anchors between their eyes. This protects a woodpecker’s brain by softening the impact of the hammering and its vibrations.</p>
<p>Research such as this is guiding the design of <a href="https://www.mdpi.com/2076-3417/11/22/10584/htm">shock absorbers and vibration control devices</a> to protect the users of such equipment. The same concept has also inspired innovations such as <a href="https://www.sciencedirect.com/science/article/pii/S2214785319341987">layered shock-absorbing structures</a> for building design.</p>
<h2>3. Building design</h2>
<p>Scallops are molluscs with a fan-shaped, corrugated external shell. The zig-zag shape of these <a href="https://www.sciencedirect.com/topics/engineering/corrugated-sheet">corrugations</a> strengthens the shell’s structure, enabling it to withstand high pressure under water.</p>
<p>The same process is used to increase the strength of a cardboard box, with corrugated paper material being glued between the two external cardboard layers. The introduction of a corrugated surface significantly increases a material’s strength, in the same way that folding a piece of paper into a zig-zag shape allows it to take an additional load.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/498782/original/file-20221204-55844-i0v9vg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/498782/original/file-20221204-55844-i0v9vg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=350&fit=crop&dpr=1 600w, https://images.theconversation.com/files/498782/original/file-20221204-55844-i0v9vg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=350&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/498782/original/file-20221204-55844-i0v9vg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=350&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/498782/original/file-20221204-55844-i0v9vg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=440&fit=crop&dpr=1 754w, https://images.theconversation.com/files/498782/original/file-20221204-55844-i0v9vg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=440&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/498782/original/file-20221204-55844-i0v9vg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=440&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A folded piece of paper in a zig-zag shape could withstand heavy load. Amin Al-Habaibeh, Author provided.</span>
</figcaption>
</figure>
<p>The dome-shaped structure of a scallop’s shell also enables it to withstand significant loads. This structure is self-supporting as it distributes the weight evenly over the entire dome shape, reducing the load on a single point. This improves the structure’s stability without the need for reinforcing steel beams and has inspired the <a href="https://www.sciencedirect.com/science/article/abs/pii/S0378778821003182">design of many buildings</a>, including St Paul’s Cathedral in London. </p>
<h2>4. Transport aerodynamics</h2>
<p>Sharks have two dorsal fins which provide several aerodynamic advantages. They <a href="https://dlnr.hawaii.gov/sharks/anatomy/fins-swimming/#:%7E:text=Dorsal%20fins%20stabilize%20the%20shark,and%20helping%20to%20conserve%20energy.">stabilise the shark</a> from rolling, while their aerofoil shape creates an area of low turbulence behind them and so increases the efficiency of the shark’s forward movement. </p>
<p>Shark fins have been replicated in motorised transportation. For example, racing cars use fins to both reduce turbulence when travelling at high speed and <a href="https://www.roadandtrack.com/motorsports/a28497386/shark-fin-race-car-wing-explained/">improve stability</a> when cornering. </p>
<p>Many road cars now have a small “shark fin” installed on their roof, which is used to integrate their <a href="https://natalexauto.com/blogs/natalex-auto-blog/what-is-the-shark-fin-on-the-roof-of-a-car">radio antenna</a>. This reduces drag compared to the traditional pole antenna.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/498796/original/file-20221204-55991-d268zz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/498796/original/file-20221204-55991-d268zz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=336&fit=crop&dpr=1 600w, https://images.theconversation.com/files/498796/original/file-20221204-55991-d268zz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=336&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/498796/original/file-20221204-55991-d268zz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=336&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/498796/original/file-20221204-55991-d268zz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=423&fit=crop&dpr=1 754w, https://images.theconversation.com/files/498796/original/file-20221204-55991-d268zz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=423&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/498796/original/file-20221204-55991-d268zz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=423&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Shark-fin antenna in a modern car. Amin Al-Habaibeh. Author provided.</span>
</figcaption>
</figure>
<p>We have also taken inspiration from nature to increase the efficiency of aircraft flight. An owl’s wings act as a <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2020.1748">suspension system</a>; by changing the position, shape and angle of their wings, they are able to <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2020.1748">reduce the effect</a> of turbulence while in flight. And <a href="https://www.nationalgeographic.co.uk/science-and-technology/2021/03/owl-wings-may-hold-the-key-to-turbulence-proof-planes">research</a> into owl flight may open the door to turbulence-free air travel in the future.</p>
<h2>5. Velcro</h2>
<p>The hook-and-loop <a href="https://www.velcro.co.uk/blog/2018/06/how-do-velcro-brand-fasteners-work/#:%7E:text=Hook%20and%20loop%20fasteners%20have,and%20loop%20fastener%20will%20be.">fastening mechanism</a> of <a href="https://www.velcro.com/news-and-blog/2016/11/an-idea-that-stuck-how-george-de-mestral-invented-the-velcro-fastener/">velcro</a> was inspired by the ability of the burrs of burdock plants to fasten to human clothing.</p>
<p>Plants use burrs to <a href="https://homeguides.sfgate.com/plants-burrs-26416.html">attach seed pods</a> to passing animals and people, in order to disperse seeds over wider areas. Burrs possess small hooks that interlock with the small loops in soft material.</p>
<p>Velcro replicates this by using a strip lined with hooks together with a fabric strip. When pressed together, the hooks attach to the loops and fasten to one another. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/498799/original/file-20221204-25475-ps5jqg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/498799/original/file-20221204-25475-ps5jqg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=244&fit=crop&dpr=1 600w, https://images.theconversation.com/files/498799/original/file-20221204-25475-ps5jqg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=244&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/498799/original/file-20221204-25475-ps5jqg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=244&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/498799/original/file-20221204-25475-ps5jqg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=307&fit=crop&dpr=1 754w, https://images.theconversation.com/files/498799/original/file-20221204-25475-ps5jqg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=307&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/498799/original/file-20221204-25475-ps5jqg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=307&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Hook and Loop structure under the microscope. Amin Al-Habaibeh, Author provided.</span>
</figcaption>
</figure>
<p>Velcro is used in a wide range of products worldwide. According to <a href="https://www.nasa.gov/offices/ipp/home/myth_tang.html#:%7E:text=Velcro%20was%20used%20during%20the,associated%20with%20the%20Space%20Program.">Nasa</a>, it was used in space during the Apollo missions from 1961 to 1972 to fix equipment in place in zero gravity.</p><img src="https://counter.theconversation.com/content/195593/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Amin Al-Habaibeh does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Humans often look to nature for the solutions to complex problems – here are five times where biological processes have inspired innovation.
Amin Al-Habaibeh, Professor of Intelligent Engineering Systems, Nottingham Trent University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/193026
2022-11-14T00:35:22Z
2022-11-14T00:35:22Z
They’re doing their best: how these 3 neighbourhood ‘pests’ deal with rainy days
<figure><img src="https://images.theconversation.com/files/493996/original/file-20221108-18-x9ma6s.jpg?ixlib=rb-1.1.0&rect=0%2C8%2C2700%2C1786&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Have you had a recent encounter with an animal you’d much rather avoid? As La Niña continues to give us rainy days, brush turkeys, bats, and cockroaches are emerging from their hide-outs. </p>
<p>We often think of them as pests, but these animals are just trying their best to cope in the heavy rain. They’re also crucial members of our urban ecosystems, and help keep the environment healthy. </p>
<p>Here’s what makes them so fascinating and important to your neighbourhood. </p>
<h2>Bats: heavy rain hinders echolocation</h2>
<p>Australia is home to multiple threatened species of <a href="https://theconversation.com/australias-threatened-bats-need-protection-from-a-silent-killer-white-nose-syndrome-129186">fruit bats and microbats</a>, such as grey-headed flying foxes, large bent-wing bats, and spectacled flying foxes. </p>
<p>They’re typically considered nuisances for their noise, mess and potential spread of diseases. But bats are often forgotten for their ability to control insect pests, disperse seeds, and pollinate plants.</p>
<p>Bats face some serious threats in La Niña conditions. They can respond to periods of heavy rain by using a special physiological adaptation called torpor. In torpor, bats will sleep more and lower their body temperature so they can use less energy.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/492061/original/file-20221027-20344-y8o5dv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/492061/original/file-20221027-20344-y8o5dv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/492061/original/file-20221027-20344-y8o5dv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/492061/original/file-20221027-20344-y8o5dv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/492061/original/file-20221027-20344-y8o5dv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/492061/original/file-20221027-20344-y8o5dv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/492061/original/file-20221027-20344-y8o5dv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Microbat sp. giving a smile (this bat was handled by a gloved, trained professional. Never pick up a bat yourself)</span>
<span class="attribution"><span class="source"> Image Credit Dieter Hochuli</span></span>
</figcaption>
</figure>
<p><a href="https://www.ausbats.org.au/uploads/4/4/9/0/44908845/meet_sydneys_microbats.pdf">Microbats</a> are abundant throughout Australian cities. They use <a href="https://theconversation.com/fruit-bats-are-the-only-bats-that-cant-and-never-could-use-echolocation-now-were-closer-to-knowing-why-153721">echolocation to see</a>, but heavy rain likely <a href="https://www.sciencedaily.com/releases/2019/02/190206115623.htm">reduces</a> this ability. </p>
<p>In 2019, Smithsonian researchers played recordings of downpours near bat roosts, and found the bats delayed emerging from their roosts. Delayed emergence can lead to disorientated bats with a reduced capacity to find food. </p>
<p>In Australia, rain may affect microbats more than fruit bats because of where they live. Many species of microbats, such as the <a href="https://www.environment.nsw.gov.au/threatenedspeciesapp/profile.aspx?id=10534">large bent-winged bat</a>, live in culverts and under bridges, where higher water levels can rush through during heavy rain periods.</p>
<p>Fruit bats, such as flying foxes, <a href="https://theconversation.com/fruit-bats-are-the-only-bats-that-cant-and-never-could-use-echolocation-now-were-closer-to-knowing-why-153721">don’t use echolocation</a>, but rain can wet their fur and lower their body temperature. So they’ll often stay put in their roosts to keep warm during heavy rain.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/fruit-bats-are-the-only-bats-that-cant-and-never-could-use-echolocation-now-were-closer-to-knowing-why-153721">Fruit bats are the only bats that can't (and never could) use echolocation. Now we're closer to knowing why</a>
</strong>
</em>
</p>
<hr>
<p>It also <a href="https://royalsocietypublishing.org/doi/10.1098/rsbl.2011.0313">costs a lot more energy</a> for a bat to fly in the rain, making it harder to maintain a steady intake of food. If there is consecutive days of rain, bats may fall from their home due to starvation. </p>
<p>If you find a fallen bat, do not touch it. Instead, contact <a href="https://www.wires.org.au/wildlife-information/flying-foxes-and-microbats">WIRES</a>. Or, wait to see if they leave once the rain clears up.</p>
<h2>Brush turkeys: reshape their mounds</h2>
<p>Brush turkeys are a type of ground nesting bird found along Australia’s east coast, from Cape York in Queensland down to Wollongong in NSW. They’re particularly vulnerable to the effects of heavy rain, which can damage or wash out their nests. </p>
<p>To incubate their eggs, brush-turkeys build enormous mounds of leaf litter and mulch. These mounds can weigh several tonnes, and can be as wide as <a href="https://www.qld.gov.au/environment/plants-animals/animals/living-with/brush-turkeys">4 metres across and up to 1 metre high</a>. These mounds often cause <a href="https://www.abc.net.au/news/2016-03-31/brush-turkeys-haunting-sydney-backyards/7287518">consternation among avid gardeners</a> and frustrated suburbanites.</p>
<p>But brush-turkeys can benefit the environment. As they <a href="https://birdlife.org.au/bird-profile/australian-brush-turkey">scratch for food and build mounds</a>, the birds help break down leaf litter and aerate the soil. This helps water and nutrients move throughout your soil, which ultimately helps your garden.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/492062/original/file-20221027-12-3pyzmd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/492062/original/file-20221027-12-3pyzmd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/492062/original/file-20221027-12-3pyzmd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/492062/original/file-20221027-12-3pyzmd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/492062/original/file-20221027-12-3pyzmd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/492062/original/file-20221027-12-3pyzmd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/492062/original/file-20221027-12-3pyzmd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Brush-turkey on a mound.</span>
<span class="attribution"><span class="source">Image Credit Matthew Hall</span></span>
</figcaption>
</figure>
<p>Winter rainfall is the trigger for males to start building their mounds, as the increased soil moisture provides the heat that incubates their eggs. However, research shows males <a href="https://www.tandfonline.com/doi/abs/10.1071/MU9880210">avoid constructing their nests</a> during long periods of heavy rain.</p>
<p>Flood waters can sweep away existing mounds and, after multiple weeks of rain, mounds can become waterlogged. Floods can drown eggs or reduce mound temperatures below the levels necessary for incubation, preventing the chicks from developing properly. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/492065/original/file-20221027-25221-sv6gb2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/492065/original/file-20221027-25221-sv6gb2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=484&fit=crop&dpr=1 600w, https://images.theconversation.com/files/492065/original/file-20221027-25221-sv6gb2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=484&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/492065/original/file-20221027-25221-sv6gb2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=484&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/492065/original/file-20221027-25221-sv6gb2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=608&fit=crop&dpr=1 754w, https://images.theconversation.com/files/492065/original/file-20221027-25221-sv6gb2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=608&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/492065/original/file-20221027-25221-sv6gb2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=608&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A brush-turkey chick.</span>
<span class="attribution"><span class="source">Image Credit John Martin</span></span>
</figcaption>
</figure>
<p>Brush-turkeys are known to protect their mounds from heavy rain. Much anecdotal evidence suggests brush-turkeys can predict the weather in advance, and <a href="http://www.climatekelpie.com.au/index.php/1999/08/01/the-brush-turkeys-are-never-wrong/">reshape their mound accordingly</a>. </p>
<p>During light rain, male brush-turkeys <a href="https://www.abc.net.au/local/stories/2011/11/23/3374445.htm">open up their mound</a>, letting much-needed moisture soak in to speed up decomposition of the leaf litter. But as strong rainfall approaches, they instead <a href="https://catalogue.nla.gov.au/Record/4385974">pile extra material on top of their mound</a>, providing an extra layer of protection and creating a more conical shape so water can run off the sides. </p>
<p>Next time, consider tuning into your local brush turkeys for a weather forecast. If you see them doing a bit of extra raking in your garden on dismal grey days, it might be a scramble to protect their nests from approaching heavy rain. </p>
<p>When you spot one, use the opportunity to snap a photo and upload it to the <a href="https://taronga.org.au/conservation-and-science/current-research/big-city-birds">Big City Birds app</a>. This app tracks where birds such as brush-turkeys occur, and how they’re adapting to city life.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/sad-and-distressing-massive-numbers-of-bird-deaths-in-australian-heatwaves-reveal-a-profound-loss-is-looming-190685">‘Sad and distressing’: massive numbers of bird deaths in Australian heatwaves reveal a profound loss is looming</a>
</strong>
</em>
</p>
<hr>
<h2>Native cockroaches: evacuate to drier areas</h2>
<p>As we settle into another wet spring, our homes are becoming perfect breeding grounds for cockroaches. The humidity of a moist house combined with warmer weather, allows for cockroaches to grow quicker and thrive. </p>
<p>Only a small handful of cockroach species will survive in the average house, and they are all introduced species. After rain, it’s vital to make your house a little less cockroach friendly. Reduce humidity by keeping the house well ventilated, and make sure to remove any food scraps.</p>
<p>On the other hand, the waterlogged soil in your local green spaces are likely home to some of <a href="https://australian.museum/learn/animals/insects/cockroaches-order-blattodea/">Australia’s 450 native species of cockroaches</a>, so you might see some around your backyard after rain. Cockroaches play important roles in the ecosystem, breaking down nutrients in the soil.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/494376/original/file-20221109-22-y2eyjf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/494376/original/file-20221109-22-y2eyjf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=643&fit=crop&dpr=1 600w, https://images.theconversation.com/files/494376/original/file-20221109-22-y2eyjf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=643&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/494376/original/file-20221109-22-y2eyjf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=643&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/494376/original/file-20221109-22-y2eyjf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=808&fit=crop&dpr=1 754w, https://images.theconversation.com/files/494376/original/file-20221109-22-y2eyjf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=808&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/494376/original/file-20221109-22-y2eyjf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=808&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Native Australian <em>Ellipsidion sp.</em> cockroach.</span>
<span class="attribution"><span class="source">Image Credit Elise Oakman</span></span>
</figcaption>
</figure>
<p>Burrowing cockroaches can be spotted because they don’t have wings. Many of our other native cockroaches are obvious due to their <a href="https://www.australiangeographic.com.au/topics/wildlife/2018/04/our-native-cockroaches-arent-as-gross-as-you-think/">beautiful colours and patterns</a>.</p>
<p>One amazing example is the <a href="https://www.sydney.edu.au/news-opinion/news/2022/10/01/extinct-wood-eating-cockroach-rediscovered-after-80-years.html">Lord Howe Island wood-feeding cockroach</a>. Thought to be extinct for some 80 years due to rats, they have only recently been rediscovered. This species is important, because it recycles nutrients and is food for other animals.</p>
<p>While native cockroaches may enter your home in an attempt to find warm dry ground, they won’t thrive indoors. If you find a native cockroach inside your house, instead of reaching for the bug spray, it’s best to catch them and put them back outside. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-large-cockroach-thought-extinct-since-the-1930s-was-just-rediscovered-on-a-small-island-in-australia-191847">A large cockroach thought extinct since the 1930s was just rediscovered on a small island in Australia</a>
</strong>
</em>
</p>
<hr>
<p>So during wet weather, take the time to remember that these animals are trying their best. All have amazing ways of adapting to heavy rain, and we should cut them some slack – the environment, including our backyards, need them.</p><img src="https://counter.theconversation.com/content/193026/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Elise Oakman receives funding from the Ecological Society of Australia, the Department of Planning and Environment, and the Australian Wildlife Society.</span></em></p><p class="fine-print"><em><span>Caitlyn Forster receives funding from the Australian Research Council. She is affiliated with the Australasian Society for the Study of Animal Behaviour and Invertebrates Australia. </span></em></p><p class="fine-print"><em><span>Matthew Hall has previously received research funding from The Australian Citizen Science Association and Birding NSW. </span></em></p><p class="fine-print"><em><span>Mei-Ting Kao does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Brush turkeys, bats, and cockroaches are crucial for the environment – including our gardens. Each have fascinating ways of coping in wet weather.
Elise Oakman, PhD Candidate, University of Sydney
Caitlyn Forster, PhD Candidate, School of Life and Environmental Sciences, University of Sydney
Matthew Hall, Casual Academic, University of Sydney
Mei-Ting Kao, PhD student, University of Sydney
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/190498
2022-10-26T16:52:30Z
2022-10-26T16:52:30Z
Declining bat populations are a cause for human concern
<figure><img src="https://images.theconversation.com/files/491514/original/file-20221025-14669-qb0tff.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5751%2C3647&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Some bat populations have had their numbers reduced by as much as 90 per cent.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/declining-bat-populations-are-a-cause-for-human-concern" width="100%" height="400"></iframe>
<p>Fewer bats will be flapping through the evening skies in the coming months. It’s the time of year where some species go into hibernation, <a href="https://www2.gov.bc.ca/assets/gov/environment/natural-resource-policy-legislation/legislation-regulation/frpa-pac/wildlife-habitat-features/whf_field_guide_kootenay_boundary_bat_hibernaculum.pdf">cozying up in narrow rock crevices or caves to overwinter</a>. </p>
<p>Fortunately, this disappearance is only seasonal. Bats are critical for the functioning of healthy ecosystems. They <a href="https://doi.org/10.1016/B978-0-12-394288-3.00007-1">help cycle nutrients in the environment and pollinate plants</a>. They also <a href="https://doi.org/10.1126/science.1201366">eat agricultural pests</a>, which reduces the need for pesticides.</p>
<p>Bats provide enormous value to our ecosystems, but because they do their work under the cover of darkness, we aren’t always aware of the help they give.</p>
<h2>Threatened habitats</h2>
<p>More worrisome than this seasonal disappearance is the fact that bat populations have been <a href="https://www.fs.usda.gov/research/news/highlights/tracking-decline-bats-north-america">declining in North America for decades</a>. Loss of habitat due to forestry, urbanization and <a href="https://doi.org/10.1007/s10980-019-00855-2">conversion of land to agriculture</a> reduces suitable habitats for bats, while pesticide application kills the insects that they feed on. </p>
<p>These impacts are exacerbated by the fungus, <em>Pseudogymnoascus destructans</em>, which causes white-nose syndrome. This fatal fungus is responsible for <a href="https://www2.gov.bc.ca/assets/gov/environment/plants-animals-and-ecosystems/wildlife-wildlife-habitat/wildlife-health/wildlife-health-documents/wns_fact_sheet_bc_bat_researchers_jan_2014.pdf">the deaths of over six million bats in North America</a>.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/XDYKSF2VEoM?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Protecting bats from white-nose syndrome in British Columbia.</span></figcaption>
</figure>
<p>White-nose syndrome has been particularly devastating in Eastern Canada where it’s caused <a href="https://publications.gc.ca/site/eng/9.579593/publication.html">an over 90 per cent decline in populations</a> of little brown myotis (<em>Myotis lucifugus</em>) and northern myotis (<em>Myotis septentrionalis</em>).</p>
<p>The fungus is making its way further west, with the <a href="https://www.cbc.ca/news/canada/saskatoon/white-nose-syndrome-detected-saskatchewan-1.6530342">first recorded case in Saskatchewan</a> in July. White-nose syndrome hasn’t been detected yet in British Columbia, but the deadly threat is looming. </p>
<p>Our research team at the B.C. node of the <a href="https://www.cwhcbc.com/">Canadian Wildlife Health Cooperative</a> has been working to support wildlife health for over a decade. To understand the threats currently facing the <a href="https://wcsbats.ca/species">15 species of bats living in British Columbia</a>, we studied 275 bats that had died between 2015 and 2020. We found that <a href="https://doi.org/10.1139/cjz-2021-0230">the most common causes of death were linked to human activity</a></p>
<p>This information can help us track bat populations over time and in response to urbanization and climate change. In order to help bats live, we need to know why they die.</p>
<h2>Killer cats</h2>
<p>A quarter of the bats in our study were killed by cats. This wasn’t surprising — domestic cats are <a href="https://doi.org/10.1071/WR19174">well-known predators of wildlife</a>. In Australia, free-roaming pet cats are estimated to kill 390 million animals a year. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/dont-let-them-out-15-ways-to-keep-your-indoor-cat-happy-138716">Don't let them out: 15 ways to keep your indoor cat happy</a>
</strong>
</em>
</p>
<hr>
<p>Free-roaming cats pose not only a <a href="https://doi.org/10.1111/mam.12240">risk to bats</a>, but also to biodiversity. Some cities in Iceland have <a href="https://hakaimagazine.com/features/its-10-pm-do-you-know-where-your-cat-is/">implemented a cat curfew</a> to save their declining bird populations. </p>
<p>One of our more surprising findings was that most of the bats we found that were killed by cats were female and in relatively good body condition. This greater proportion of dead female bats might be due to <a href="https://bcbats.ca/attachments/Living-with-Bats-FINAL.pdf">cats entering maternity roosts</a> where female bats give birth to and raise their young. </p>
<p>Because bats have relatively <a href="https://doi.org/10.1007/s11284-012-1010-0">few young each year</a>, the death of female bats in otherwise good condition has outsized implications for their population numbers into the future. </p>
<p>The simplest solution here is to keep pet cats indoors and supervise outdoor cat time. Cats only bring about <a href="https://doi.org/10.1016/j.biocon.2013.01.008">20 per cent of their prey home</a>, so owners likely aren’t aware of the extent of their feline friends’ hunting habits.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/491677/original/file-20221025-246-wflr31.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a cat holding a dead mouse in its mouth" src="https://images.theconversation.com/files/491677/original/file-20221025-246-wflr31.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/491677/original/file-20221025-246-wflr31.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/491677/original/file-20221025-246-wflr31.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/491677/original/file-20221025-246-wflr31.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/491677/original/file-20221025-246-wflr31.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/491677/original/file-20221025-246-wflr31.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/491677/original/file-20221025-246-wflr31.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Cats only bring home a fraction of what they kill.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>Recent research suggests that <a href="https://doi.org/10.1016/j.biocon.2022.109503">these actions are most important near forested areas</a>. Cats were found to be more likely to prey on wildlife closer than 500 metres to forests rather than further away. Focusing on managing cats who live near forested areas could be one way to minimize risks to wildlife.</p>
<p>Keeping cats inside has benefits for cats too: Indoor cats <a href="https://spca.bc.ca/faqs/indoor-cats-vs-outdoor-cats/">live longer</a> than cats that live outside. </p>
<h2>Worlds collide</h2>
<p>Half of the bats in our study died by human-associated causes. That’s partly because the bats we studied were submitted to our lab by members of the public. Most of the bats in our study (90 per cent) were synanthropic species, those who live alongside people.</p>
<p>Reflecting these close contacts, another 25 per cent of bats in this study died due to blunt force trauma, such as through vehicle or garage door collisions.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/491676/original/file-20221025-246-8913bd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a green sign on a brick wall reading BAT ROOST KEEP OUT!" src="https://images.theconversation.com/files/491676/original/file-20221025-246-8913bd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/491676/original/file-20221025-246-8913bd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=598&fit=crop&dpr=1 600w, https://images.theconversation.com/files/491676/original/file-20221025-246-8913bd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=598&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/491676/original/file-20221025-246-8913bd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=598&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/491676/original/file-20221025-246-8913bd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=751&fit=crop&dpr=1 754w, https://images.theconversation.com/files/491676/original/file-20221025-246-8913bd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=751&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/491676/original/file-20221025-246-8913bd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=751&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Bat conservation programs in the United Kingdom include wildlife laws that protect ecosystem balance.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>Interestingly, bats that died in this way were more likely to be male. It’s not entirely clear why this is, but research suggests that males may <a href="https://doi.org/10.1111/mam.12072">fly further than females</a>, increasing their likelihood of collisions with cars or buildings.</p>
<p>Understanding differences in death by sex is helpful because it can inform conservation and management. For example, identifying where bats fly and how far could determine where to construct new roadways. The creation of <a href="https://doi.org/10.1016/j.ecoleng.2021.106466">wildlife crossings</a> in busy bat areas could also help reduce fatalities. </p>
<h2>An incomplete picture</h2>
<p>Studying wildlife isn’t easy. Bats roost in lots of different places, from caves to barns to attics, and scientists can’t monitor bats in all places at all times. </p>
<p>Reports from communities contribute to the information gathered about bats, and help us to understand the health of local bat populations. </p>
<p>To study bat mortality, we use an approach called “<a href="https://doi.org/10.1186/s43170-020-00016-5">passive surveillance</a>,” where the public is an essential research partner. Those who find sick or dead wildlife can report it online to the Canadian Wildlife Health Cooperative <a href="http://www.cwhc-rcsf.ca/report_and_submit.php">using this tool</a>. In B.C. you can report bats specifically through the <a href="https://bcbats.ca/got-bats/report-your-bats/">Community Bat Program of B.C.</a>. You can also learn more about creating bat friendly spaces in the <a href="https://bcbats.ca/attachments/BC-Bat-friendly-Communities-Guide-2018.pdf">Bat Friendly Communities Guide</a>.</p>
<p><em>This article is based on research led by Western College of Veterinary Medicine student Imara Beattie with the British Columbia node of the Canadian Wildlife Health Cooperative.</em></p><img src="https://counter.theconversation.com/content/190498/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kaylee Byers is the Deputy Director for the British Columbia node of the Canadian Wildlife Health Cooperative. </span></em></p>
Bats have important roles to play in ecosystems, but their populations have been declining due to disease and habitat change.
Kaylee Byers, Regional Deputy Director, British Columbia Node of the Canadian Wildlife Health Cooperative; University Research Associate, Simon Fraser University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/190578
2022-09-29T19:16:14Z
2022-09-29T19:16:14Z
The night is full of animal life, but scientists know very little about it
<figure><img src="https://images.theconversation.com/files/484547/original/file-20220914-18-xmkk2a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Naturalists and life scientists have long debated how insect-eating bats navigate their dark world.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/bats-flying-against-sun-golden-sky-129518465">Sarun T/Shutterstock</a></span></figcaption></figure><p>Human disturbance is rapidly changing the nature of the nocturnal world. Intensive farming, suburban spread, artificially lit cities, and continuously busy road systems mean <a href="https://pubmed.ncbi.nlm.nih.gov/29903973/">daytime species</a> are becoming increasingly active throughout the night. Ecologists <a href="https://pubmed.ncbi.nlm.nih.gov/25225371/">suggest</a> that the majority of land animals are either nocturnal or active across both the day and night. </p>
<p><a href="https://theconversation.com/too-hot-to-sleep-nights-are-warming-faster-than-days-as-earth-heats-up-186958">Recent research</a> has also shown that the night is warming considerably faster than the day. The stifling night-time heat experienced across Europe this summer is indicative of this, placing nocturnal animals under even greater stress. </p>
<p>The transforming night adds new sensory pressures concerning finding food, a mate, and navigating a world permeated by artificial illumination. Environmental change is severely threatening the ability of nocturnal animals to coexist with humans. The conservation of nocturnal species has therefore become urgent. </p>
<p>Despite the abundance of night-time life, the understanding of nocturnal species has evaded science throughout history. Physical restraints on human navigation in the dark are partially responsible for this. This scientific blind spot is referred to as the “nocturnal problem”.</p>
<p>The legacy of this inaccessibility remains a barrier to our understanding of nocturnal life today. However, given the environmental threat now facing the nocturnal world, this will have profound consequences should it remain unaddressed. A better understanding of nocturnal life is critical to ensure its effective protection.</p>
<h2>The origins of the ‘nocturnal problem’</h2>
<p>So how did the nocturnal problem arise and why does it still impede science?</p>
<p>Constrained by their own reliance on vision, early scientists struggled to imagine the different ways in which animals might navigate in the dark. The myths that built up around familiar nocturnal creatures, such as hedgehogs, are evidence of historical attempts to fill the scientific gap.</p>
<p>The Greek philosopher Aristotle suggested that hedgehogs poached apples and carried them off on their spines. Such mythology was commonly included within Victorian natural history texts as an introduction to more factual descriptions of hedgehog anatomy, such as their capacity for smell and other bodily adaptations.</p>
<figure class="align-center ">
<img alt="A hedgehog passing a road with a car light illuminating the background." src="https://images.theconversation.com/files/484573/original/file-20220914-4859-6nr6ho.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/484573/original/file-20220914-4859-6nr6ho.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/484573/original/file-20220914-4859-6nr6ho.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/484573/original/file-20220914-4859-6nr6ho.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/484573/original/file-20220914-4859-6nr6ho.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/484573/original/file-20220914-4859-6nr6ho.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/484573/original/file-20220914-4859-6nr6ho.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Even the experiences of hedgehogs remain to some degree unknown.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/hedgehog-passing-street-night-car-lights-1280471914">Lukasz Walas/Shutterstock</a></span>
</figcaption>
</figure>
<p>But even artificial illumination afforded very limited access. Illumination fundamentally changes the nature of the nocturnal world, with impacts on animal behaviour. A good example is the attraction of moths to street lights.</p>
<p>The historical debate surrounding how insect-eating bats navigate their dark world illustrates the problem. Numerous attempts have been made to understand bat senses. However, it was not until the late 1930s, more than 150 years after experimentation on bats had begun, that the scientists Donald R. Griffin and Robert Galambos identified echolocation – the ability to navigate via the emission and detection of sound signals. </p>
<p>Griffin would later describe the secrets of bat senses as a “magic well”, acknowledging the fundamental challenge of comprehending senses so different from our own. </p>
<p>But efforts to understand nocturnal senses could only take scientists so far. In 1940, American naturalist Orlando Park declared that the biological sciences suffered from a “nocturnal problem”, in reference to the continued inability to understand the nocturnal world. This was reflected in the more recent philosophical text of Thomas Nagel, which posed the question <a href="https://warwick.ac.uk/fac/cross_fac/iatl/study/ugmodules/humananimalstudies/lectures/32/nagel_bat.pdf">what it like is to like to be a bat?</a></p>
<h2>Persistence of the nocturnal problem</h2>
<p>Despite technological developments, including the introduction of infrared photography, aspects of nocturnal life continue to elude modern science. </p>
<p>While technology has afforded scientists a much better understanding of echolocation in bats, our way of thinking about bat senses remains limited by our own dependence on vision. When describing echolocation, scientists still suggest that <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3172592/">bats “see” using echoes</a>. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1296266269008654336"}"></div></p>
<p>The elusive Australian Night Parrot was presumed extinct for much of the 20th century. Although they have been <a href="https://www.nytimes.com/2022/01/04/science/night-parrot-ghost-bird-australia.html">recently rediscovered</a>, scientists remain unable to estimate their population size accurately while questions over the threats facing the species persist. </p>
<p>Despite an improvement in scientific research, nocturnal life remains understudied. In 2019, life scientist <a href="https://www.journals.uchicago.edu/doi/full/10.1086/702250">Kevin J. Gaston</a> called for an expansion of research into nocturnal life. History shows us that when there are scientific gaps in knowledge about the night, cultures create their own truths to fill those gaps. The consequences of doing so may be significant. </p>
<p>The night is ecologically rich and efforts to fill these gaps in scientific understanding should be prioritised. The nocturnal world is threatened by environmental change, and its future depends on our commitment to getting to know the darkness.</p><img src="https://counter.theconversation.com/content/190578/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dr Andy Flack received funding for this research from the Arts and Humanities Research Council. The funding relates to the project 'Dark-dwellers as more-than-human misfits'.</span></em></p><p class="fine-print"><em><span>Alice Would was a Research Associate on Dr Andy Flack's AHRC Leadership Fellows Project 'dark-dwellers as more-than-human misfits.' </span></em></p>
Humans have long struggled to understand the nocturnal world. As environmental change becomes increasingly acute, understanding their lives has never been more critical.
Andy Flack, Senior Lecturer in Modern and Environmental History, University of Bristol
Alice Would, Lecturer in Imperial and Environmental History, University of Bristol
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/187542
2022-07-23T09:34:39Z
2022-07-23T09:34:39Z
The Marburg virus: urgent need to contain this close cousin of Ebola
<figure><img src="https://images.theconversation.com/files/475615/original/file-20220722-18-62rym.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Roger Harris/Science Photo Library</span></span></figcaption></figure><p><em>The Marburg virus is a highly infectious disease that’s in the same family as the virus that causes Ebola. The Conversation Africa’s Wale Fatade and Usifo Omozokpea asked virologist Oyewale Tomori about its origin and how people can protect themselves against the disease.</em></p>
<h2>What is the Marburg virus and where did it come from?</h2>
<p>Marburg virus causes the Marburg Virus Disease (MVD), formerly known as Marburg haemorrhagic fever. The virus, which belongs to the same family as the Ebola virus, causes severe viral haemorrhagic fever in humans with an average case fatality rate of <a href="https://www.cdc.gov/vhf/marburg/index.html">around</a> 50%. It has varied <a href="https://www.cdc.gov/vhf/marburg/index.html">between</a> 24% to 88% in different outbreaks depending on virus strain and case management. </p>
<p>It was <a href="https://www.who.int/news-room/fact-sheets/detail/marburg-virus-disease">first reported</a> in 1967 in a town called Marburg in Germany and in Belgrade, Yugoslavia (now Serbia). There were simultaneous outbreaks in both cities. It came from monkeys imported from Uganda for laboratory studies in Marburg. The laboratory staff got infected as a result of working with materials (blood, tissues and cells) of the monkeys. Of 31 cases associated with these outbreaks, seven people died.</p>
<p>After the initial outbreaks, other cases have been reported in different parts of the world. <a href="https://www.who.int/news-room/fact-sheets/detail/marburg-virus-disease">Most were in Africa</a> – Uganda, the Democratic Republic of Congo, Kenya, South Africa, and more recently in Guinea and Ghana. Serological <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6968259/">studies</a> have also revealed evidence of past Marburg virus infection in Nigeria. </p>
<p>While the host, or reservoir, of the virus is not conclusively identified, the virus has been <a href="https://www.who.int/news-room/fact-sheets/detail/marburg-virus-disease">associated with fruit bats</a>. <a href="https://www.who.int/news-room/fact-sheets/detail/marburg-virus-disease">In 2008</a>, two independent cases were reported in travellers who had visited a cave inhabited by Rousettus bat colonies in Uganda.</p>
<h2>How is it spread?</h2>
<p>It is spread through contact with materials (fluids, blood, tissues and cells) of an infected host or reservoir. In the case of the monkeys from Uganda imported into Marburg, laboratory staff obviously got infected through contact with the tissues and the blood of the monkeys. </p>
<p>There can also be human-to-human transmission via <a href="https://www.who.int/news-room/fact-sheets/detail/marburg-virus-disease">direct contact</a> (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids of infected people, and with surfaces and materials. This includes materials like bedding, and clothing contaminated with these fluids.</p>
<p>But there’s a great deal we don’t know. For example, whether contact with bat droppings in caves can cause infections in people. </p>
<h2>What are the symptoms? And how bad can they be?</h2>
<p>After an incubation period of between 2 to 21 days, there is a sudden onset of the disease marked by fever, chills, headache, and myalgia. </p>
<p>Around the fifth day after the onset of symptoms, maculopapular rash, most prominent on the trunk (chest, back, stomach), <a href="https://www.cdc.gov/vhf/marburg/symptoms/index.html">may appear</a>. Nausea, vomiting, chest pain, a sore throat, abdominal pain, and diarrhea may appear. Symptoms become increasingly severe and can include jaundice, inflammation of the pancreas, severe weight loss, delirium, shock, liver failure, massive hemorrhaging, and multi-organ dysfunction.</p>
<p>The <a href="https://www.who.int/news-room/fact-sheets/detail/marburg-virus-disease">mortality is around 50%</a>, and could be as high as 88% or as low as 20%. </p>
<h2>Can it be treated?</h2>
<p>Not really, but <a href="https://www.who.int/news-room/fact-sheets/detail/marburg-virus-disease">early supportive care</a> with rehydration, and symptomatic treatment, improves survival. </p>
<h2>What can people do to protect themselves?</h2>
<p>Avoid exposure to the virus as much as possible, and protect against discharges from infected people. </p>
<p>Also, because of the similarities in the symptoms of many hemorrhagic fever diseases, especially during the early stages, there is a need for reliable laboratory confirmation of a case of Marburg virus infection. And once that is done – as with Ebola – the person must immediately be isolated and avoid contact with other people. </p>
<h2>What should be done to ensure the virus doesn’t spread?</h2>
<p>There is no holiday from disease outbreaks. That means as a country, surveillance cannot take a break or a holiday.</p>
<p>When cases are reported, it’s time to be on the alert. Proper screening is called for. Arrivals from the affected country and other neighbouring countries must be checked at the ports of entry. </p>
<p>Studies <a href="https://www.ajtmh.org/view/journals/tpmd/38/2/article-p407.xml">done in Nigeria in the the 1980s</a> and more recently in the 1990s provide evidence of possible previous infections with Marburg virus – or a related virus – in certain Nigerian populations. This leads me to believe that the virus is probably more widespread than we think it is. We need an improvement in diagnosis which can help us do the detection as quickly, and as efficiently as possible.</p>
<p>On top of this, countries need to improve their disease surveillance and laboratory diagnosis to enhance and improve the capacity for a more definitive diagnosis of viral hemorrhagic fever infections.</p><img src="https://counter.theconversation.com/content/187542/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Oyewale Tomori does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
The chances of surviving Marburg are improved if there’s early supportive care with rehydration and symptomatic treatment.
Oyewale Tomori, Fellow, Nigerian Academy of Science
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/173613
2022-06-12T12:11:32Z
2022-06-12T12:11:32Z
Cats that are allowed to roam can spread diseases to humans and wildlife
<figure><img src="https://images.theconversation.com/files/467255/original/file-20220606-13103-fk8xfg.jpg?ixlib=rb-1.1.0&rect=7%2C15%2C5077%2C3369&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Domestic cats are allowed to roam can transmit parasites and diseases to humans and wildlife.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/cats-that-are-allowed-to-roam-can-spread-diseases-to-humans-and-wildlife" width="100%" height="400"></iframe>
<p>For decades, scientists have warned that ecologically destructive activities increase the risk of <a href="https://doi.org/10.1126/science.287.5452.443">diseases spilling over between wildlife and human populations</a>. Examples of these drivers include climate change, <a href="https://doi.org/10.1038/nature09575">habitat loss, wildlife trafficking</a>, environmental contamination, expansion of anthropocentric activities and invasive species introduction. </p>
<p>Domestic animals also contribute to the movement of diseases between species. Free-roaming domestic animals, like cats, can facilitate the spread and transfer of diseases, impacting both humans and wildlife.</p>
<h2>Infectious parasites</h2>
<p>Free-roaming cats — which include feral, stray and house cats — present a particularly compelling case because of their large population sizes and their central role in the life cycle of a parasite called <em>Toxoplasma gondii</em> (<em>T. gondii</em>) that infects both wildlife and humans. Most people may have only heard of toxoplasmosis from their doctors during a pregnancy or <a href="https://www.science.org/content/article/reality-check-can-cat-poop-cause-mental-illness">in articles on “brain-altering” parasites</a>. </p>
<p>However, <em>T. gondii</em> is one of the most common zoonotic parasites globally and is estimated to affect <a href="https://doi.org/10.1371/journal.pone.0090203">about 30 to 50 per cent of the global human population</a>. <em>T. gondii</em> infections can have <a href="https://doi.org/10.1016/J.PT.2017.04.001">severe and life-threatening consequences</a>; especially for immunocompromised people and infants infected during pregnancy.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/467258/original/file-20220606-18-9z8rjl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a woman in a pink shirt holds a black cat" src="https://images.theconversation.com/files/467258/original/file-20220606-18-9z8rjl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/467258/original/file-20220606-18-9z8rjl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/467258/original/file-20220606-18-9z8rjl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/467258/original/file-20220606-18-9z8rjl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/467258/original/file-20220606-18-9z8rjl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/467258/original/file-20220606-18-9z8rjl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/467258/original/file-20220606-18-9z8rjl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Pregnant women are often advised to avoid interacting with cat feces because of the risk posed to their unborn children.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p><em>Toxoplasma gondii</em> forms a permanent resting tissue cyst in the muscle or nervous tissue of a host, so even healthy infected people are impacted. Chronic toxoplasma infections have been linked with illnesses including degenerative neurological diseases, schizophrenia and <a href="https://doi.org/10.1016/j.canep.2022.102119">brain cancer</a>. </p>
<p>Domestic cats or wild felids — like lions, jaguars or cougars — <a href="https://www.routledge.com/Toxoplasmosis-of-Animals-and-Humans/Dubey/p/book/9780367543129">intermittently excrete millions of <em>T. gondii</em> eggs (called oocysts)</a> into the environment <a href="https://doi.org/10.1016/j.vetpar.2017.10.021">through their feces</a>. These oocysts persist under favourable conditions for years in water and soil, <a href="https://doi.org/10.1371/journal.pone.0255664">with the capacity for long-distance dispersal</a>.</p>
<p>If any warm-blooded animal ingests an oocyst, it can become infected with <em>T. gondii</em>. This can happen if a person or animal ingests oocysts in contaminated water or food, or through eating another animal that has already become infected.</p>
<h2>Spreading diseases</h2>
<p>Although both wild felids and domestic cats are sources of toxoplasma, domestic cats outnumber wild felids by several orders of magnitude. We recently tested whether mammals living in environments with greater densities of domestic cats would show higher infection rates of <em>T. gondii</em>. </p>
<p>While there are no global data sets showing domestic cat densities, domestic cats are closely associated with humans, and therefore, measures of human population density can act as a surrogate for the density of free-roaming cats. Using data from over 200 studies, we demonstrated that indeed, <a href="https://doi.org/10.1098/rspb.2021.1724">wildlife living in areas of higher human density</a> had higher infection rates of <em>T. gondii</em>. </p>
<p>We concluded that this higher infection rate occurred due to a combination of two phenomenon: high densities of free-roaming domestic cats producing infected feces, and the loss of natural habitats. Natural ecosystems have important roles in filtering, sequestering and <a href="https://doi.org/10.1128/AEM.01435-10">removing <em>T. gondii</em></a> and <a href="https://doi.org/10.1023/A:1013169401211">other pathogens</a> from human, livestock and wildlife exposure pathways. Breaking the lifecycle by preventing cats from hunting and landscape restoration are key preventative measures.</p>
<p>If wildlife have an increased risk of exposure to <em>T. gondii</em> in certain areas, then humans and livestock can also be unintended targets. Public health researchers have shown this repeatedly by <a href="https://doi.org/10.1016/j.vetpar.2014.08.003">sampling soil</a>, <a href="https://doi.org/10.1007/s10096-011-1414-8">vegetable gardens</a> and <a href="https://doi.org/10.1016/j.vetpar.2010.02.045">playgrounds</a>.</p>
<h2>Rabies risk</h2>
<p>Rabies is another disease whose risk is increased by free-roaming cats. In the United States, cats are <a href="https://doi.org/10.2460/JAVMA.258.11.1205">the most common rabies positive domestic species</a>, with cats posing <a href="https://doi.org/10.1111/zph.12077">two-and-a-half times the rabies exposure risk compared to bats in Pennsylvania</a>. In Canada, we recently found similar public health concerns of free-roaming cats when we <a href="https://doi.org/10.1371/JOURNAL.PGPH.0000357">examined patterns of rabies submissions of bats in Canada</a>. </p>
<p>In Canada, free-roaming cats were associated with 10 times more bats being submitted for rabies testing compared to indoor cats. In fact, in our dataset, there were five records of free-roaming cats bringing bats into the house that subsequently were found to be rabies positive. This hunting activity by cats is obviously dangerous for people in the household, and is a very simple explanation for cases of cryptic rabies infections (rabies cases without an identifiable source).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/467910/original/file-20220609-12-wecu74.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a silver-haired bat" src="https://images.theconversation.com/files/467910/original/file-20220609-12-wecu74.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/467910/original/file-20220609-12-wecu74.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=394&fit=crop&dpr=1 600w, https://images.theconversation.com/files/467910/original/file-20220609-12-wecu74.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=394&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/467910/original/file-20220609-12-wecu74.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=394&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/467910/original/file-20220609-12-wecu74.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=495&fit=crop&dpr=1 754w, https://images.theconversation.com/files/467910/original/file-20220609-12-wecu74.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=495&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/467910/original/file-20220609-12-wecu74.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=495&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">In areas with large numbers of free-roaming cats predating bats, the risk that a human will be exposed to rabies is expected to increase.</span>
<span class="attribution"><span class="source">(Jared Hobbs)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>This risk is directly proportionate to the frequency of free-roaming cats killing bats, which is unfortunately common. Single cats have been known to <a href="https://doi.org/10.1080/03014223.2011.649770">kill a hundred bats in a week</a>. </p>
<p>In our dataset, one free-roaming cat killed nine endangered little brown bats in one month, with another record of a cat killing 14 bats in a single evening. Many bat populations have undergone severe declines, especially due to <a href="https://doi.org/10.1111/nyas.14045">an introduced fungal disease</a>. Bats are <a href="https://doi.org/10.1007/s11284-012-1010-0">long-lived with low reproduction</a>, so this additional source of mortality can severely impact bat populations.</p>
<p>Since cats only bring home <a href="https://doi.org/10.1016/j.biocon.2013.01.008">20 per cent of what they kill</a>, prey returns and rabies submissions only provide a tiny glimpse of the true cat predation rates. It is therefore apparent that although natural rabies prevalence in bats is low — <a href="https://doi.org/10.7589/0090-3558-47.1.64">less than one per cent</a> — in areas with cats killing large numbers of bats, rabies exposure risks will increase.</p>
<h2>Protecting health and wildlife</h2>
<p>There is broad consensus among <a href="https://www.canadianveterinarians.net/policy-and-outreach/position-statements/statements/free-roaming-owned-abandoned-and-feral-cats/">veterinarians</a>, <a href="https://doi.org/10.1016/j.biocon.2019.04.002">ecologists</a>, <a href="https://doi.org/10.1111/j.1863-2378.2012.01522.x">public health experts</a> and <a href="https://www.peta.org/about-peta/why-peta/feral-cats/">animal rights activists</a> that free roaming by domestic cats is detrimental for feline welfare, wildlife welfare, conservation and human health. Wildlife have the same capacity for distress and pain as domestic animals, and perform irreplaceable ecosystem services with <a href="https://doi.org/10.1007/s11284-012-1010-0">tangible economic benefits</a>, making their predation unjustifiable from an ethical or economic perspective. </p>
<p>Free-roaming cats suffer from increased mortality through <a href="https://doi.org/10.2460/javma.2004.225.1377">traumatic injury, disease, neglect and abandonment</a>. This marginalization of cats needs to be replaced with <a href="https://www.adventurecats.org/about/">progressive enrichment resources</a> and <a href="https://doi.org/10.1111/CSP2.12706">responsible management that does not foster an inhumane and biased disregard</a> for feline welfare standards, wildlife welfare, conservation and human health. </p>
<p><em>David Lapen, research scientist with Agriculture and Agri-Food Canada, co-authored this article.</em></p><img src="https://counter.theconversation.com/content/173613/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Amy Wilson has done research contract work for Environment and Climate Change Canada. </span></em></p><p class="fine-print"><em><span>Scott Wilson works for and receives research funding from Environment and Climate Change Canada </span></em></p>
Allowing cats to roam unsupervised is detrimental to humans, wildlife and the cats themselves. Managing free-roaming cats should consider the risks they pose to other species.
Amy Wilson, Adjunct Professor, Forest and Conservation Sciences, University of British Columbia
Scott Wilson, Adjunct Professor, Forest and Conservation Sciences, University of British Columbia
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/183233
2022-06-10T03:44:55Z
2022-06-10T03:44:55Z
One of Australia’s tiniest mammals is heading for extinction – but you can help
<figure><img src="https://images.theconversation.com/files/464885/original/file-20220523-20-2vqrve.JPG?ixlib=rb-1.1.0&rect=6%2C0%2C4573%2C3449&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Lindy Lumsden</span>, <span class="license">Author provided</span></span></figcaption></figure><p>They weigh around 15 grams, the same as a 50 cent coin. They devour vast quantities of insects. And they’re in real trouble. </p>
<p>Our <a href="https://www.nature.com/articles/s41598-022-11404-4">new research</a> has found the critically endangered southern bent-wing bat is continuing to decline. Its populations are centred on just three “maternity” caves in southeast South Australia and southwest Victoria, where the bats give birth and raise their young. At night, mothers leave their pups clustered in a “creche” on the cave ceiling while they head out to <a href="http://www.publish.csiro.au/?paper=WR21052%22%22">hunt for moths</a>, including agricultural pest species. These beautiful bats have already lost 90% of the natural vegetation in their range due to land clearing. Now they face a drying climate. </p>
<p>Our research tracked thousands of these bats and found new mother bats and their young were not surviving well, especially in drought conditions. Our modelling shows they will be near extinct within 36 years, with declines of up to 97%. That’s just three generations of bat. </p>
<p>To stop them <a href="https://theconversation.com/scientists-re-counted-australias-extinct-species-and-the-result-is-devastating-127611">following other species</a> into extinction, these bats need <a href="https://theconversation.com/threat-of-extinction-demands-fast-and-decisive-action-7985">urgent action</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/467645/original/file-20220608-24-qf6mit.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="bent wing bat in hands" src="https://images.theconversation.com/files/467645/original/file-20220608-24-qf6mit.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/467645/original/file-20220608-24-qf6mit.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/467645/original/file-20220608-24-qf6mit.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/467645/original/file-20220608-24-qf6mit.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/467645/original/file-20220608-24-qf6mit.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/467645/original/file-20220608-24-qf6mit.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/467645/original/file-20220608-24-qf6mit.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">These bats are sensitive to disturbance and have a limited range.</span>
<span class="attribution"><span class="source">Emmi van Harten</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Why are these bats in such trouble?</h2>
<p>Most cave-roosting bats are highly threatened in Australia, with 62% of species listed as threatened at a state or national level. </p>
<p>While we don’t often see them, bats make up one quarter of all Australian mammal species. They play <a href="https://theconversation.com/why-we-shouldnt-be-so-quick-to-demonise-bats-87693">vital roles</a> in our ecosystems, with microbats like the southern bent-wing bat feeding on insects, including <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/ece3.5901">agricultural pests</a>. Fruit bats like flying-foxes are important long-distance pollinators and seed dispersers. Despite this, Australian bats are <a href="http://doi.wiley.com/10.1111/mam.12066">under-studied and under-funded</a> for research and conservation.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/australias-threatened-bats-need-protection-from-a-silent-killer-white-nose-syndrome-129186">Australia's threatened bats need protection from a silent killer: white-nose syndrome</a>
</strong>
</em>
</p>
<hr>
<p>Bats themselves don’t make it easy. They can be incredibly difficult to study. While many Australians are familiar with our spectacular flying-foxes as they pass by at night, most of our <a href="https://www.ausbats.org.au/species-list.html">81 bat species</a> are very small. They are also agile flyers, making them difficult to catch. It is particularly difficult to capture the same bats many times to study critical aspects of their biology such as survival rates.</p>
<p>With the help of a huge team of volunteers, we <a href="http://www.publish.csiro.au/?paper=AM19024">safely tagged</a> almost 3,000 southern bent-wing bats with small <a href="https://www.abc.net.au/news/2016-06-21/tracking-a-thousand-bats-study-sheds-light-on-secretive-species/7528666">microchips</a>. </p>
<p>The tags let us detect these bats as they flew in and out of an important cave at <a href="https://theconversation.com/naracoorte-where-half-a-million-years-of-biodiversity-and-climate-history-are-trapped-in-caves-78603">Naracoorte Caves</a> in South Australia. With this approach, we were able to gather <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/ece3.5482">millions of detections</a> over a three and a half-year period, without having to catch the same bats again and again. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1054360969189543938"}"></div></p>
<p>So what did we find? We found the <a href="https://www.nature.com/articles/s41598-022-11404-4">lowest adult survival</a> rates amongst female bats who had just given birth and were nursing pups compared to males and non-breeding females. Young bats recently independent from their mothers also had low survival rates.</p>
<p>We used these survival results to model future scenarios for the South Australian population and found predicted declines, with sharper drops during droughts. If these rates of decline continue across the total population, the species will be close to extinct within <a href="http://www.environment.gov.au/biodiversity/threatened/species/pubs/87645-conservation-advice-14062021.pdf">three generations</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/467649/original/file-20220608-22-evrq24.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="bent wing bat" src="https://images.theconversation.com/files/467649/original/file-20220608-22-evrq24.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/467649/original/file-20220608-22-evrq24.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=420&fit=crop&dpr=1 600w, https://images.theconversation.com/files/467649/original/file-20220608-22-evrq24.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=420&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/467649/original/file-20220608-22-evrq24.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=420&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/467649/original/file-20220608-22-evrq24.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=528&fit=crop&dpr=1 754w, https://images.theconversation.com/files/467649/original/file-20220608-22-evrq24.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=528&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/467649/original/file-20220608-22-evrq24.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=528&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The southern bent-wing bat in flight.</span>
<span class="attribution"><span class="source">Steve Bourne, Wikimedia Commons</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Droughts can have devastating effects on our wildlife, with the most damage done to our <a href="https://theconversation.com/we-must-strengthen-not-weaken-environmental-protections-during-drought-or-face-irreversible-loss-102901">most threatened species</a>. Worse, droughts take place against a backdrop of existing threats such as the widespread clearance of natural habitats. </p>
<p>As drought and bushfires worsen as the the climate changes, they can impact large proportions of the habitat remaining for some species. The <a href="https://theconversation.com/a-staggering-1-8-million-hectares-burned-in-high-severity-fires-during-australias-black-summer-157883">Black Summer</a> bushfires contributed to the listing of the closely-related eastern bent-wing bat as critically endangered in Victoria.</p>
<p>These threats pose particular risks for cave bats because their hunting range is limited by the locations of suitable caves. Although southern bent-wing bats are highly mobile and can fly <a href="https://doi.org/10.1071/WR21088">more than 70km</a> between caves in just a few hours, most bats gather at the three maternity caves for much of the year. This means food and water need to be available around these key sites to support the populations.</p>
<p>Unfortunately, 90% of natural vegetation in the southern bent-wing bat’s range has been cleared and most of the region’s wetlands have either been drained and converted to agricultural land, or are <a href="https://www.waterconnect.sa.gov.au/Content/(https://www.waterconnect.sa.gov.au/Content/Publications(https://www.waterconnect.sa.gov.au/Content/Publications/DEW/Temporal%20changes%20in%20wetland%20hydrology%20using%20WOfS.pdf">drying out</a> due to a combination of groundwater extraction and a drying climate. </p>
<h2>What needs to be done?</h2>
<p>Australia’s recent extinctions have shown the need to <a href="http://doi.wiley.com/10.1111/j.1755-263X.2012.00239.x">act quickly</a>. In response to these threats, the southern bent-wing bat now has a <a href="https://www.swifft.net.au/cb_pages/team_southern_bent-wing_bat_-_recovery_team.php">national recovery team</a> of species experts, researchers, vets, land managers and representatives from government agencies, zoos and NGOs. This team is implementing the <a href="https://www.awe.gov.au/sites/default/files/documents/recovery-plan-southern-bent-wing-bat.pdf">national recovery plan</a> for this bat in a bid to prevent extinction and see it recover to a healthy population. </p>
<p>But we can’t leave it all to this group. We can help this and other endangered bats on these four fronts: </p>
<ul>
<li><p>take action to help reduce the impacts of climate change, such as worsening droughts, megafires and heat events</p></li>
<li><p>help community efforts to restore natural landscapes by planting trees and native vegetation and restoring wetlands</p></li>
<li><p>avoid entering caves known to have bats in them, as the southern bent-wing bat and several other species are highly sensitive to disturbance</p></li>
<li><p>share why <a href="https://theconversation.com/no-aussie-bats-wont-give-you-covid-19-we-rely-on-them-more-than-you-think-137168">bats are important</a> and in need of our protection. </p></li>
</ul>
<p>This year, we’ve had the welcome news that the eastern barred bandicoot has <a href="https://www.abc.net.au/news/2021-09-15/endangered-eastern-barred-bandicoot-no-longer-extinct-in-wild/100462530">recovered significantly</a>, from being listed as extinct in the wild on the Australian mainland to endangered. </p>
<p>This remarkable result shows sustained conservation effort can bring back even species teetering right on the edge of extinction. We can do the same for the southern bent-wing bat. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/australias-next-government-must-tackle-our-collapsing-ecosystems-and-extinction-crisis-182048">Australia's next government must tackle our collapsing ecosystems and extinction crisis</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/183233/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Emmi van Harten received funding from the Australian Government Research Training Program Scholarship, Australian Speleological Federation Karst Conservation Fund, Holsworth Wildlife Research Endowment, Lirabenda Endowment Fund and the South Australian Department of Environment and Water. She is Coordinator of the Southern Bent-wing Bat National Recovery Team through Zoos Victoria’s Department of Wildlife Conservation and Science.</span></em></p><p class="fine-print"><em><span>Lindy Lumsden works for the Arthur Rylah Institute for Environmental Research, Department of Environment, Land, Water and Planning. She is the Chair of the Southern Bent-wing Bat National Recovery Team and Vice-President of the Australasian Bat Society. </span></em></p><p class="fine-print"><em><span>Thomas Prowse receives funding from the ARC, NHMRC, and Commonwealth and State environment departments. He is a board member of The Wilderness Society South Australia.</span></em></p>
Already critically endangered, the southern bent-wing bat is still declining in a drying climate. If we don’t step in, it will likely be extinct within three generations of bat.
Emmi van Harten, Lecturer in Ecology, La Trobe University
Lindy Lumsden, Principal Research Scientist, Arthur Rylah Institute for Environmental Research
Thomas Prowse, Postdoctoral research fellow, School of Mathematical Sciences, University of Adelaide
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/183274
2022-06-06T15:06:49Z
2022-06-06T15:06:49Z
Fruit bats: the winged ‘conservationists’ reforesting parts of Africa
<figure><img src="https://images.theconversation.com/files/464223/original/file-20220519-12-gbhj28.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A fruit bat.</span> <span class="attribution"><span class="source">Subphoto.com/Shutterstock</span></span></figcaption></figure><p><a href="https://www.worldlandtrust.org/species/mammals/straw-coloured-fruit-bat/">Straw-coloured fruit bats</a> exist throughout most of the African continent. This large fruit bat is one of, if not the most numerous fruit-eating animal (called frugivores) in Africa. They live in colonies of thousands to millions of individuals.</p>
<p>Fruit bats sleep during the day, hanging upside down in the crowns of old trees, and become active at sunset when they set off in search of food – specifically nectar and fruit.</p>
<p>With their wingspan of up to 80cm, they are able to cover vast distances. When the colonies are very large and competition for food is stiff, they can fly up to 95km to suitable food trees and only return to their roosts the following morning. They defecate the seeds of the fruit they eat over an unusually long time period, even during flight. They can thus disperse seeds across huge areas as they go. </p>
<p>The seeds transported in this way can end up far from the parent plant, and in areas that are good for germination and establishment. The fact that these gigantic colonies seasonally migrate across Africa, following the rain and upcoming fruit, help disperse seeds of seasonal fruit and in places with only a few local frugivores.</p>
<p>The fruit bats therefore contribute to the <a href="https://www.mpg.de/biodiversity">species and genetic diversity of forests</a>. </p>
<p>In 2019 we <a href="https://www.cell.com/current-biology/fulltext/S0960-9822(19)30203-9?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982219302039%3Fshowall%3Dtrue">investigated</a> the potential of these fruit bat colonies to reforest areas where trees had been lost in parts of Africa.</p>
<p>We tracked the movements of fruit bats in Ghana, Burkina Faso and Zambia by deploying them with small GPS loggers, which allowed us to follow their nightly movements to food trees. We also looked into how long they held food in their gut. We then applied our findings to entire colonies to see what services they provided in large numbers. </p>
<p>We found that, in a conservative estimate, a colony of 150,000 animals could disseminate more than 300,000 small seeds in a single night, and that a single colony of fruit bats could kickstart the regrowth of 800 hectares of forest.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/466238/original/file-20220531-16-at1viv.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map with blue and yellow. Lines showing animal dispersal habits" src="https://images.theconversation.com/files/466238/original/file-20220531-16-at1viv.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/466238/original/file-20220531-16-at1viv.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=194&fit=crop&dpr=1 600w, https://images.theconversation.com/files/466238/original/file-20220531-16-at1viv.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=194&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/466238/original/file-20220531-16-at1viv.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=194&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/466238/original/file-20220531-16-at1viv.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=244&fit=crop&dpr=1 754w, https://images.theconversation.com/files/466238/original/file-20220531-16-at1viv.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=244&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/466238/original/file-20220531-16-at1viv.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=244&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Routes of bats and animal seed couriers.</span>
<span class="attribution"><span class="source">Author supplied © MPG</span></span>
</figcaption>
</figure>
<p>They’ve likely often done so – a <a href="https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358809">study</a> using seed traps deforested areas in Cote d'Ivoire found that 96% of dropped seeds were carried in by fruit bats. </p>
<p>Worryingly, fruit bats have <a href="https://www.sciencedirect.com/science/article/pii/S0960982219302039">started to disappear</a> from forests everywhere. They are primarily <a href="https://www.frontiersin.org/articles/10.3389/fevo.2021.641411/full">at risk from</a> <a href="https://www.cambridge.org/core/journals/oryx/article/bats-as-bushmeat-a-global-review/747260E678F188D0A89E8A6966DEFBA5">hunting</a> and persecution out of superstition, fear or simple annoyance due to the <a href="https://www.ingentaconnect.com/content/miiz/actac/2014/00000016/00000001/art00008">noise</a> they make when they roost. </p>
<p>This would not only lead to a loss in biodiversity but have huge economic consequences as fruit bats disperse the seeds of, and likely pollinate as well, many economically valuable plants such as timber species and food producing plants. </p>
<h2>Spreading seeds</h2>
<p>For our study, we used GPS transmitters to track the flight paths of the bats. We also measured the time it took them to excrete the seeds after eating them. For this we took bats into captivity, fed them their natural food dyed with fluorescent dye and then filmed when which food item was excreted. These showed that the animals only excrete some of the seeds after a relatively long time, thereby facilitating their dispersal over vast distances. </p>
<p>We were able to calculate the potential of an entire colony to disseminate seeds over long distances and to transport them to deforested areas. </p>
<iframe width="100%" height="315" src="https://www.youtube.com/embed/eq2iesVsIgE" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe>
<p>Among other things, the straw-coloured fruit bat disperses fast-growing trees that are the first to colonise open ground, so-called pioneer trees, and which are able to grow in bright sunlight, creating the right environment for rainforest tree species to establish and grow. </p>
<p>The profit that the regrowth of this much forest generates for the population, for example through edible fruits, increased soil fertility and timber, has been estimated using the results from a <a href="https://doi.org/10.1016/j.ecolecon.2011.08.012">study</a> on the cost of deforestation in Ghana under the assumption that all areas supplied with seeds by bats were allowed to reforest. Our estimate was in excess of 700,000 Euro (about US$750,000). Because the straw-coloured fruit bats migrate throughout Africa, many communities profit from their services.</p>
<h2>In decline</h2>
<p>Sadly, the population of straw-coloured fruits bats is in continuous decline. For example a colony we monitor in Accra, Ghana, has gone down from one million individuals over a decade ago to less than 20,000 bats in the spring of 2022. </p>
<p>Given that each female gives birth to a single pup each year, this is going to lead to a population collapse. Logging the large trees in which the animals live is also threatening their populations. Often we will return to a place where a thriving colony was previously observed only to find their roost trees and thus the bats, gone.</p>
<p>The straw-coloured fruit bats contribute to the conservation of African forests, so there is an urgent need to explain their importance to the human population. With the recent COVID-outbreak and other diseases such as Ebola, bats have moved into the focus of the press and thus local communities. While it is important to inform people about how to safely co-exist with the bats, there is currently no scientific evidence to support the rumour that straw-coloured fruit bats or any bat may have been involved in these outbreaks. The best way to ensure the health and safety of both bats and people is to simply stay away from them.</p>
<p>During our research, we met a local king in Kibi, a town in southern Ghana, who is leading by example. He’s placed the straw-coloured fruit bat colony that has taken up residence in his garden under his own personal protection and calls them their babies. </p>
<p>An NGO we collaborate with closely – the <a href="https://www.rwandawildlife.org/">Rwanda Wildlife Corporation</a> – does exemplary work to help mitigate the negative trend of fruit bat populations. They visit local communities, inform them about the benefits and threats the bats offer, and recruit local volunteers to contribute to counts and observations. Many of these volunteers are children, which are our best ambassadors for a future where humans and bats can live side by side.</p><img src="https://counter.theconversation.com/content/183274/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Fruit bats have the potential to reforest areas where trees had been lost in parts of Africa.
Dina Dechmann, Researcher, Max Planck Institute of Animal Behavior
Mariëlle van Toor, Researcher, Linnaeus University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/182880
2022-05-17T18:31:53Z
2022-05-17T18:31:53Z
On the trail of the origins of Covid-19
<figure><img src="https://images.theconversation.com/files/462448/original/file-20220511-14-wmpaxu.jpg?ixlib=rb-1.1.0&rect=0%2C23%2C4000%2C2215&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cave inhabited by bats.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/fr/image-photo/huge-group-bats-waits-patiently-exit-1440955400">Sanatana/Shutterstock</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>As the Covid-19 virus (coronavirus SARS-CoV-2) continues to spread and claim victims worldwide, its <a href="https://www.nature.com/articles/d41586-022-00732-0">origins</a> remain unknown. Each scientific community puts forward its own <a href="https://www.theguardian.com/world/2021/dec/31/why-hunt-for-covid-origins-still-wrapped-in-politics-impasse-china-west">theory</a>, with some suggesting the virus may have leaked out of a <a href="https://theconversation.com/covid-19-why-the-lab-leak-theory-must-be-formally-investigated-161297">laboratory</a>.</p>
<p>Another theory, based on recent studies of the <a href="https://www.science.org/content/article/do-three-new-studies-add-proof-covid-19-s-origin-wuhan-animal-market">Wuhan wet market</a> in China, along with others carried out in <a href="https://www.nature.com/articles/s41467-021-26809-4">Cambodia</a>, <a href="https://www.nature.com/articles/s41586-022-04532-4">Laos, Japan, China, and Thailand</a>, posits that an ancestral virus in rhinolophus bats went on from infecting wild and/or domestic animals to humans. Indeed, in these different studies, several viruses with genetic sequences very similar to SARS-CoV-2 were isolated in these bats.</p>
<h2>A missing link</h2>
<p>Though it has been shown some bat species have hosted these coronaviruses naturally, the wild or domestic animal (or animals) that acted as a bridge between them and humans – the missing link – remains unidentified. Pangolins were first suspected, but now appear to have been collateral victims rather than one of these much-talked-about missing links. A coronavirus genome sequence detected in pangolins was indeed related to that of SARS-CoV-2, but the rest of the genome was <a href="https://link.springer.com/article/10.1007/s10311-020-01151-1">too distant from it genetically</a> to back the hypothesis.</p>
<p>Moreover, the pangolins hosts in which the viruses that were genetically close to SARS-CoV-2 were found had mostly been confiscated at live-animal markets, at the end of the supply chain. As a result, they had been in lengthy contact with other animal species. It is very likely they were infected along this supply chain rather than in their natural environment. <a href="https://theconversation.com/origin-of-the-covid-19-virus-the-trail-of-mink-farming-155989">Mink farms</a> were also suspected of being an intermediate host in China.</p>
<p>Lastly, pangolins and rhinolophus bats do not share the same habitat, making it highly unlikely there was any contact between the two species in which the virus jumped from one to the other. On the other hand, civets and raccoon dogs could be an intermediate source of <a href="https://pubmed.ncbi.nlm.nih.gov/16140765/">SARS-CoV-1</a>). Rodents or primates could also carry pathogens with zoonotic potential, such as hantaviruses – which can cause haemorrhagic fever with renal syndrome – or filoviruses, <a href="https://www.pnas.org/doi/10.1073/pnas.2002324118">which include the Ebola virus</a>. The latter is passed on to humans through wild animals, in particular bats, antelopes, and primates such as chimpanzees and gorillas, then spreads among humans, mainly by direct contact with blood, secretions and other bodily fluids from infected people. The average case fatality rate is around 50%.</p>
<p>In 2013, initial cases of disease from the Ebola virus were detected in <a href="https://pubmed.ncbi.nlm.nih.gov/34424896">West Africa</a>. The rise of these cases led to over 10,000 deaths, mainly in Guinea, Liberia, and Sierra Leone.</p>
<h2>The risky habit of bushmeat-eating</h2>
<p>Activities such as hunting, animal-handling or eating meat from wild animals therefore create the conditions for viruses to spread from animals to humans – a potentially devastating phenomenon called “spillover”.</p>
<p>The <a href="https://www.cirad.fr/en/cirad-news/news/2020/science/covid-19-zoocov-a-new-project-to-prevent-coronavirus-transmission-from-wildlife-to-humans">ZooCov</a> project has sought to define and quantify this risk in Cambodia. For almost two years – and right from the start of the pandemic – it has adopted a <a href="https://www.oie.int/en/what-we-do/global-initiatives/one-health/">“One Health”</a> approach to explore whether – and how – pathogens such as coronaviruses can be passed on to humans from wild animals that are hunted and eaten.</p>
<p>Indeed, in South-East Asia, wild animals are regularly traded, and bushmeat is customarily eaten. This eating habit is often opportunistic. In some communities, it complements a low-protein diet. It can also be frequent and targeted. In Cambodia, 77% of 107 families interviewed in the ZooCov project said they had eaten bushmeat in the <a href="https://www.cirad.fr/en/cirad-news/news/2022/coronavirus-surveillance-a-concrete-example-of-the-one-health-approach-in-action-in-cambodia">past month</a>.</p>
<p>Use for medicinal purposes is also widespread. In Vietnam, an <a href="https://pubmed.ncbi.nlm.nih.gov/35356028/">analysis of records</a> of the Vietnamese authorities confiscating pangolins and related by-products between 2016 and 2020 reported 1,342 live pangolins (6,330 kg), 759 dead pangolins or pangolin carcasses (3,305 kg), and 43,902 kg of pangolin scales.</p>
<p>Yet this consumption also has a cultural and social dimension that is still not properly understood. Among the well-off – and often in big cities – people sometimes eat bushmeat out of a desire for social status, and a belief that eating it endows them with the physical or physiological <a href="https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30063-3/fulltext">attributes</a> of the animal. They also sometimes eat bushmeat out of rejection of industrially produced meat, considered unhealthy. Animals are widely reared to meet this demand and the demand for <a href="https://www.who.int/publications/i/item/WHO-2019-nCoV-fur-farming-risk-assessment-2021.1">fur production</a>.</p>
<p>In the Stung Treng and Mondolkiri provinces of Cambodia, where protected forest areas remain, researchers surveyed more than 900 people living on the edge of these forests to determine the structure of the illegal bushmeat trade. Statistical analyses are underway to identify the people most at risk of contact with wildlife thus with such pathogens. We already know those exposed are mostly young middle-class men, and that some communities are more exposed than others. Sociological studies have also helped better grasp today’s context: the legal framework, the profiles of players in the trade, their motives and deterrents in trade and consumption of wild animals, and how the context has changed with each different health crisis (bird flu, Ebola, SARS-CoV-1, etc.).</p>
<h2>Which populations are most at risk?</h2>
<p>These successive crises seem to have scarcely affected the habits of these communities. Beyond regularly eating bushmeat, one fourth of the families surveyed said they still hunted or ensnared wild animals, and 11% claimed to sell bushmeat or wild animals. Furthermore, in the same areas of study, over 2,000 samples taken from wild animals trafficked or eaten for subsistence – bats, rodents, turtles, monkeys, birds, wild pigs, etc. – were analysed. Some of these samples tested positive for coronaviruses and scientists at the Institut Pasteur du Cambodge (IPC) are currently sequencing their genome in a bid to learn more about their origin, evolution, and zoonotic potential. Finally, researchers collected blood samples from over 900 people from the same region to find out whether they had been in contact with a coronavirus or coronaviruses. These analyses are still underway, but what we do know is that these people had not been exposed to SARS-CoV-2 when the survey was conducted.</p>
<p>If the Covid crisis has taught us anything, it is the importance of detecting such emergences early in order to nip the pathogens in the bud. While many questions remain about the way cases emerge, there are just as many questions about the monitoring systems that should be set up to track them. The results of the ZooCov project will be used to develop a system for detecting spillover of zoonotic viruses early, particularly by strengthening the system for monitoring wildlife health that is already in operation in Cambodia, which was set up by the <a href="https://cambodia.wcs.org/Initiatives/Wildlife-Health.aspx">Wildlife Conservation Society</a> (WCS). Other large-scale projects in research and development will help us understand, detect, and prevent these phenomena of emerging cases.</p>
<hr>
<p><em>The authors would like to thank Cambodia’s Ministry of Health, its Ministry of Agriculture, Forestry and Fisheries, and its Ministry of Environment, as well as all the project’s partners: Institut Pasteur du Cambodge (IPC), the Wildlife Conservation Society (WCS), Flora and Fauna International (FFI), Institut de Recherche pour le Développement (IRD), Hong Kong University (HKU), the GREASE network, International Development Enterprise (iDE), the World Wildlife Fund (WWF), Elephant Livelihood Initiative Environment (ELIE), BirdLife International, Jahoo, and World Hope International.</em></p>
<p><em>Translated from the French by Thomas Young for <a href="http://www.fastforword.fr/en">Fast ForWord</a>.</em></p><img src="https://counter.theconversation.com/content/182880/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Véronique Chevalier a reçu des financements de l'Agence Nationale de la Recherche (ANR), la Région Occitanie et la Fondation Pasteur.</span></em></p><p class="fine-print"><em><span>François Roger et Julia Guillebaud ne travaillent pas, ne conseillent pas, ne possèdent pas de parts, ne reçoivent pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'ont déclaré aucune autre affiliation que leur poste universitaire.</span></em></p>
Scientists exploring the possibility of an animal origin for Covid-19 are still investigating the missing link between bats and human beings.
Véronique Chevalier, Veterinarian epidemiologist, Cirad
François Roger, Directeur régional Asie du Sud-Est, vétérinaire et épidémiologiste, Cirad
Julia Guillebaud, Ingénieure de recherche , Institut Pasteur
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/175673
2022-02-21T12:30:59Z
2022-02-21T12:30:59Z
Moths and bats have been in an evolutionary battle for millions of years – and we’re still uncovering their tricks
<figure><img src="https://images.theconversation.com/files/445412/original/file-20220209-25-wpmyla.jpeg?ixlib=rb-1.1.0&rect=0%2C0%2C3003%2C1994&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Moths have evolved extraordinary tricks to fend off bat attacks.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Todd_Cravens_2017_(Unsplash).jpg">Todd Cravens/Wikimedia</a></span></figcaption></figure><p>There aren’t many better examples of two species embroiled in an intense struggle for survival than bats and moths. These two animals are the archetype of an <a href="https://theconversation.com/explainer-the-evolutionary-arms-race-between-bats-and-moths-43675">evolutionary arms race</a>, with each trying to one-up the other in the battle of survival between predator and prey.</p>
<p>Bats first evolved the ability to <a href="https://www.discoverwildlife.com/animal-facts/what-is-echolocation/">echolocate</a> around 65 million years ago. By producing high frequency “clicks” with their mouth or nose and listening for echoes bouncing off objects, bats are able to illuminate the world around them with sound.</p>
<p>Echolocation allows bats to exploit hunting opportunities unavailable to other aerial predators. By hunting at night, they have the opportunity to pursue and consume nocturnal insects. </p>
<p>This ability has put huge pressure on the insects that bats target, such as crickets, lacewings and grasshoppers. That means many of these insects have evolved an extraordinary range of <a href="https://www.bionity.com/en/encyclopedia/Adaptation.html">counter-adaptations</a> to help them survive. And in no species are these so evident as in moths.</p>
<p>Many moths have evolved ears that are sensitive to bat echolocation calls. This allows them to hear bats approaching and take evasive action, like hiding in foliage or flying away. </p>
<p>Some moths have even <a href="https://prelights.biologists.com/highlights/anti-bat-ultrasound-production-in-moths-is-globally-and-phylogenetically-widespread/">evolved</a> to produce sounds of their own, alerting bats that they are toxic. If a species emits high frequency clicks that are audible to an attacking bat, the bat will quickly learn to associate a clicking moth with a bad taste: and will stop targeting them altogether. </p>
<p>The clicks of some moth species are even able to “jam” bats’ echolocation calls. By timing their clicks to overlap with the clicks of an approaching bat, moths are able to confuse the bat, making it harder for it to reach its target.</p>
<h2>Absorbing sound</h2>
<p>At the <a href="https://research-information.bris.ac.uk/en/persons/thomas-r-neil">University of Bristol</a>, my colleagues and I are most interested in the defences of moths that don’t have ears. If they can’t hear an approaching bat, how might they increase their chances of survival? Moths without ears would have to have evolved <a href="https://www.nature.com/articles/srep35600">passive defences</a>, meaning adaptations that are present all the time, regardless of whether a moth is under threat from a nearby bat or not. </p>
<p>Recently, we’ve uncovered two such adaptations in moth species without ears. The first is <a href="https://www.nature.com/articles/news980827-6">acoustic camouflage</a>. This is the sound equivalent of visual camouflage: when an octopus <a href="https://www.youtube.com/watch?v=PmDTtkZlMwM">blends perfectly</a> into a rock, or an insect looks <a href="https://www.youtube.com/watch?v=C7R_Zjz1IoI">exactly like</a> a leaf.</p>
<figure class="align-center ">
<img alt="A beige-coloured moth" src="https://images.theconversation.com/files/446479/original/file-20220215-23-zihx8x.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/446479/original/file-20220215-23-zihx8x.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/446479/original/file-20220215-23-zihx8x.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/446479/original/file-20220215-23-zihx8x.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/446479/original/file-20220215-23-zihx8x.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/446479/original/file-20220215-23-zihx8x.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/446479/original/file-20220215-23-zihx8x.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Antheraea pernyi, a species of earless moth, has evolved sound-absorbent wings that act as acoustic camouflage.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>To achieve this, earless moths have evolved <a href="https://www.newscientist.com/article/2260621-earless-moths-have-acoustic-camouflage-that-protects-them-from-bats/">specialised scales</a> on their wings and body that absorb sound energy from an echolocating bat, causing the bat to receive a diminished echo from the moth’s body. By dampening the sound in this way, the moth is able to literally disappear from an echolocating bat’s “view” of the night sky.</p>
<p>The way that these scales are able to absorb sound is quite spectacular. Each scale on a moth wing vibrates in response to sound waves, but the scales all vibrate at slightly different frequencies. So working together, the scales are able to absorb sound at all the <a href="https://dnr.maryland.gov/wildlife/Pages/plants_wildlife/bats/batelocu.aspx">frequencies</a> bats use for hunting, which span from 11 kilohertz to 212 kilohertz. </p>
<p>By vibrating, the scales dissipate sound energy by converting it to kinetic energy and heat. The lessons we’ve learned from these scales will hopefully help us create thinner <a href="https://www.acoustiblok.co.uk/soundproofing-materials/">sound-absorbing</a> materials to line walls of buildings like music studios and buildings on busy residential roads, making the world a quieter place for all.</p>
<h2>Diverting attacks</h2>
<p>Another adaptation we’ve identified in moths is an <a href="https://scitechdaily.com/moth-wingtips-structured-to-reflect-sound-an-acoustic-decoy-to-thwart-bat-attack/">acoustic decoy</a>. This can be thought of as the sound equivalent to <a href="https://www.nhm.ac.uk/discover/why-do-butterflies-have-eyespots.html">eyespots</a> seen in fish and butterflies. The idea is to divert a predator’s attack away from the vital body parts of an animal, such as their head, towards more expendable appendages like fins and wings that could be lost without fatal damage. </p>
<p>In moths, these decoys take the form of elongated, twisted structures on the wingtips. Some moths also have long hindwings that end in a similar shape, known as streamer decoys. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/446481/original/file-20220215-15-x7febc.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A diagram showing examples of streamer decoys in two different moth species" src="https://images.theconversation.com/files/446481/original/file-20220215-15-x7febc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/446481/original/file-20220215-15-x7febc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=569&fit=crop&dpr=1 600w, https://images.theconversation.com/files/446481/original/file-20220215-15-x7febc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=569&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/446481/original/file-20220215-15-x7febc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=569&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/446481/original/file-20220215-15-x7febc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=716&fit=crop&dpr=1 754w, https://images.theconversation.com/files/446481/original/file-20220215-15-x7febc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=716&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/446481/original/file-20220215-15-x7febc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=716&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Examples of streamer decoys in two different moth species.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The unique, undulating shape of these structures means that these body parts are excellent at reflecting sound, as well as scattering it over many different angles. Our research has shown that bats will attack these <a href="https://rosarubicondior.blogspot.com/2021/09/unintelligent-designer-news-batty.html">streamers</a> rather than the vulnerable body of the moth itself. This makes it more likely for moths to survive bat attacks and live another day. </p>
<p>As we uncover new and fascinating tricks like these, it’s likely that we’re only just beginning to understand all the adaptations that these species have evolved. There is already some <a href="https://www.popsci.com/animals/bat-ear-echolocation-evolution/">evidence</a> that bats have changed their echolocation calls to sneak up on insects that have ears, whilst it remains to be seen if they can overcome other forms of defence such as acoustic camouflage. It seems moths currently have the upper hand in this arms race, but bats probably have a few tricks up their wings to fight them.</p><img src="https://counter.theconversation.com/content/175673/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Thomas Neil receives funding from Engineering and Physical Sciences Research Council (EPSRC) . </span></em></p>
Research has revealed how earless moths manage to avoid bat attacks - by evolving sophisticated acoustic tricks.
Thomas Neil, Postdoctoral Research Associate in Biological Sciences, University of Bristol
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/173691
2021-12-16T13:09:18Z
2021-12-16T13:09:18Z
Curious Kids: why do bats pass diseases to humans?
<figure><img src="https://images.theconversation.com/files/438017/original/file-20211216-13-1c0e90j.jpg?ixlib=rb-1.1.0&rect=561%2C26%2C3843%2C2416&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The greater shortnosed fruit bat. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/bat-greater-shortnosed-fruit-flying-night-573073945">Nuwat Phansuwan/Shutterstock</a></span></figcaption></figure><p><strong>Why do bats pass deadly diseases like ebola to humans? – Sreehari, aged nine, Kerala, India</strong></p>
<p>This is a great question – and it’s one that doctors and scientists have been investigating for a while. The reasons bats pass lots of diseases to humans have to do with their unique lifestyle and how they have evolved. </p>
<p>Bats are both more likely than other animals to have a wide variety of diseases like Ebola, rabies and coronaviruses and more likely to pass them on to us.</p>
<h2>Flight and defence against disease</h2>
<p>Bats are the only freely flying mammals, and a lot of their biology is about flight. Flying requires lots of energy, so bats have to eat high-quality diets. A diet of leaves, which are low in energy, would not be enough for most bats. They generally prefer sugar and <a href="https://www.wildlifeonline.me.uk/animals/article/bats-diet">protein-rich foods</a> like fruit, pollen, insects, spiders, small animals and even blood. </p>
<hr>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/282267/original/file-20190702-126345-1np1y7m.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/282267/original/file-20190702-126345-1np1y7m.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/282267/original/file-20190702-126345-1np1y7m.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/282267/original/file-20190702-126345-1np1y7m.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/282267/original/file-20190702-126345-1np1y7m.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/282267/original/file-20190702-126345-1np1y7m.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/282267/original/file-20190702-126345-1np1y7m.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em><a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a> is a series by <a href="https://theconversation.com/uk">The Conversation</a> that gives children the chance to have their questions about the world answered by experts. If you have a question you’d like an expert to answer, send it to <a href="mailto:curiouskids@theconversation.com">curiouskids@theconversation.com</a> and make sure you include the asker’s first name, age and town or city. We won’t be able to answer every question, but we’ll do our very best.</em></p>
<hr>
<p>Most of a bat’s energy is needed to power its wings, so other systems in its body have evolved to be very efficient. The immune system is a particularly good example. Scientists have shown again and again that when a bat gets a disease that would be serious or fatal to humans, they <a href="https://www.sciencedaily.com/releases/2019/02/190226112401.htm">barely seem to get ill</a>. </p>
<p>Where your body might have to fight hard to beat a disease, making you ill in the process, a bat’s body just tolerates it. This means they stay healthy and able to fly and feed when infected. </p>
<p>In fact, a bat’s body is so good at tolerating diseases that they just tend to have more of them than we do. This means that even a healthy-looking bat can be a carrier for several diseases. </p>
<h2>Bats are sociable and long-lived</h2>
<p>Most bats <a href="https://academic.oup.com/bioscience/article/58/8/737/381072">live in large social groups</a> and interact closely with one another. They take care of other group members – vampire bats, for instance, <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2012.2573">regurgitate food</a> for friends that have not managed to find any. Bats also <a href="https://royalsocietypublishing.org/doi/10.1098/rsbl.2018.0860">live longer</a>, on average, than other mammals of a similar size. Size is linked to lifespan, with larger animals typically living longer and more slowly. </p>
<figure class="align-center ">
<img alt="bats hanging from roof" src="https://images.theconversation.com/files/438019/original/file-20211216-25-16y7x4v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/438019/original/file-20211216-25-16y7x4v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=429&fit=crop&dpr=1 600w, https://images.theconversation.com/files/438019/original/file-20211216-25-16y7x4v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=429&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/438019/original/file-20211216-25-16y7x4v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=429&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/438019/original/file-20211216-25-16y7x4v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=539&fit=crop&dpr=1 754w, https://images.theconversation.com/files/438019/original/file-20211216-25-16y7x4v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=539&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/438019/original/file-20211216-25-16y7x4v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=539&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Lesser dog-faced fruit bats roosting together.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/lesser-dogfaced-fruit-bat-cyneropterus-brachyotis-1309383595">Lillian Tveit/Shutterstock</a></span>
</figcaption>
</figure>
<p>When we remember that bats also tolerate disease well, we can see that being very social means that members of a typical bat population are likely to pass a lot of diseases to each other – and are unlikely to die in the process. </p>
<p>This makes a typical bat group something of a hotbed for disease. It also means that diseases that can infect bats have a good chance of mutating into new forms. Since the bats’ immune systems protect them from illness, the diseases can sit tight inside nice warm bat bodies for months or years, and have plenty of time to evolve. This is why bats might be important sources of new diseases, as well as passing on older ones.</p>
<h2>Flying brings bats closer to us</h2>
<p>Bats are found around the world, and there are lots of them – <a href="https://www.sciencefocus.com/nature/why-are-there-so-many-species-of-bat/">over 1,200 different species</a>. This means we are never too far from a bat – especially as they can fly long distances. </p>
<p>In some parts of the world you don’t have to worry as long as you don’t handle bats. Insect-eating bats, for instance, only transmit diseases to humans by direct contact or by contaminating food with their poo (which is very rare). </p>
<p>In other places, bats might be eating the same fruit as local humans. Humans can then pick up diseases from bat saliva. In some cases, bats themselves are eaten by humans. As bats can look healthy even when they are not, eating a bat is particularly risky.</p><img src="https://counter.theconversation.com/content/173691/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Isabelle Catherine Winder does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
A bat’s body is really good at tolerating diseases.
Isabelle Catherine Winder, Senior Lecturer in Zoology, Bangor University
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