tag:theconversation.com,2011:/uk/topics/amphibians-2888/articlesAmphibians – The Conversation2023-10-30T19:10:53Ztag:theconversation.com,2011:article/2160062023-10-30T19:10:53Z2023-10-30T19:10:53ZWe need a single list of all life on Earth – and most taxonomists now agree on how to start<figure><img src="https://images.theconversation.com/files/556256/original/file-20231027-21-nxmtp5.jpg?ixlib=rb-1.1.0&rect=151%2C53%2C4719%2C3316&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/common-kingfisher-alcedo-atthis-wetlands-birdss-2331210013">Sumruay Rattanataipob/Shutterstock</a></span></figcaption></figure><p>Species lists are one of the unseen pillars of science and society. Lists of species underpin our understanding of the natural world, threatened species management, quarantine, disease control and <a href="https://link.springer.com/article/10.1007/s13127-021-00518-8">much else besides</a>. </p>
<p>The people who describe new species and create lists of them are taxonomists. <a href="https://www.nature.com/articles/546025a">A few years ago</a>, a headline in the journal Nature accused the taxonomic community of anarchy for not coordinating a common view of species, leading to confusion about our knowledge of life on earth.</p>
<p>Many in the taxonomic community <a href="https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.2005075">took umbrage</a> at this. Taxonomists were concerned that the ideas proposed would limit their freedom of expression and they would be tied to a bureaucracy before they could publish new species descriptions.</p>
<p>Taxonomists certainly argue – disputation is <a href="https://link.springer.com/article/10.1007/s13127-021-00495-y">essential to the practice of taxonomy</a>, as it is to science in general. Ultimately, however, a taxonomist’s life is spent trying to discern order in the extraordinarily diverse tree of life.</p>
<p>The results of a new survey published today in the <a href="https://www.pnas.org/cgi/doi/10.1073/pnas.2306899120">Proceedings of the National Academies of Science</a>, show just how much taxonomists really do like order.</p>
<h2>Hardly a group of anarchists</h2>
<p>The argument was about how to solve disagreements between taxonomists. Eventually, the <a href="https://theconversation.com/how-a-scientific-spat-over-how-to-name-species-turned-into-a-big-plus-for-nature-138887">two sides came together</a> to produce principles on the creation of a <a href="https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3000736">single authoritative list of species</a>.</p>
<p>This group then went to the taxonomic community to survey their views on whether a global species list is needed and how it should be run.</p>
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Read more:
<a href="https://theconversation.com/how-a-scientific-spat-over-how-to-name-species-turned-into-a-big-plus-for-nature-138887">How a scientific spat over how to name species turned into a big plus for nature</a>
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<p>The newly published results show that a large majority (77%) of respondents – which included over 1,100 taxonomists and users of taxonomy across 74 countries – have expressed support for having a single list of all life on Earth.</p>
<p>They also agreed there should be a governance system that supports the list’s creation and maintenance. Just what that governance system would entail is not yet specified. Deciding that will be the next step in the process.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/556258/original/file-20231027-15-lpxxvk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A small grey animal looking like a cross between a kangaroo and a rat" src="https://images.theconversation.com/files/556258/original/file-20231027-15-lpxxvk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/556258/original/file-20231027-15-lpxxvk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/556258/original/file-20231027-15-lpxxvk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/556258/original/file-20231027-15-lpxxvk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/556258/original/file-20231027-15-lpxxvk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/556258/original/file-20231027-15-lpxxvk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/556258/original/file-20231027-15-lpxxvk.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>
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<span class="caption">Understanding species taxonomy is crucial for their management. Knowing the taxonomy of marsupials like this bettong helps identify what needs conserving and where.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/bettong-australias-smallest-kangaroo-glances-curiously-1658557687">Tyrrannoid/Shutterstock</a></span>
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<h2>Taxonomists propose hypotheses, not facts</h2>
<p>Why is this important? Many may not realise that when a taxonomist names a new species description, they are proposing a scientific hypothesis, not presenting an <a href="https://link.springer.com/book/10.1007/978-3-319-44966-1">objective scientific fact</a>.</p>
<p>Other taxonomists then look at the evidence provided in the description and decide whether they agree. If people making species lists judge that there is agreement about a hypothesis, the new species goes on their list. </p>
<p>Only after a species is listed can it be protected, studied, eradicated, ignored or whatever else governments decide is appropriate. Scientists and conservation advocates also need species to be listed before they can include them in their work. Until listed, the species remains, for all practical purposes, invisible. </p>
<p>However, not all lists are equally trusted. Very rarely taxonomists do go rogue. One notorious taxonomist has been blacklisted for “<a href="https://academic.oup.com/biolinnean/article/133/3/645/6240088?login=falsename">taxonomic vandalism</a>”. He published all sorts of new names – some even commemorated his dog – with little justification. If accepted, his field (herpetology) would have been thrown into chaos.</p>
<p>The work of rogue taxonomists wastes everyone’s time and money. In one instance, poor taxonomy has even killed people – an antivenom labelled with the wrong name for a snake was distributed in Africa and Papua New Guinea <a href="https://pubmed.ncbi.nlm.nih.gov/18359053/">with disastrous results</a>.</p>
<p>Even without rogue taxonomists, there is an enormous problem with so-called synonyms – different people giving different names for the same species. Some species have tens of scientific names, not to mention misspellings. </p>
<p>This leaves users uncertain what name to use. Sometimes they use different names but mean the same species; sometimes the same names but mean different species. The only way to clarify this confusion is by having a working master list of species names linked to the scientific literature.</p>
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<a href="https://images.theconversation.com/files/556257/original/file-20231027-17-f2a7fd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A colourful coral reef with schools of fish and a turtle swimming above it" src="https://images.theconversation.com/files/556257/original/file-20231027-17-f2a7fd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/556257/original/file-20231027-17-f2a7fd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/556257/original/file-20231027-17-f2a7fd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/556257/original/file-20231027-17-f2a7fd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/556257/original/file-20231027-17-f2a7fd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/556257/original/file-20231027-17-f2a7fd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/556257/original/file-20231027-17-f2a7fd.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>
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<span class="caption">Biodiversity is an essential feature of our planet and its ecosystems – but to understand it, we also need to understand the individual species.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/tropical-fish-turtle-red-sea-egypt-211006552">Vlad61/Shutterstock</a></span>
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<h2>Now what?</h2>
<p>The newly released survey shows taxonomists and users of taxonomy have achieved an agreement that good lists need good governance. Species lists need to reflect the best science, independent of outside influence. They need dispute resolution processes. And they need involvement and agreement from the taxonomic community on their contents.</p>
<p>Governance of science does not work unless a large majority of scientists agree with the rules, because participation is voluntary. There’s no such thing as science police. </p>
<p>Agreement and compliance is best achieved if scientists themselves are involved in the creation of the rules. This helps to increase buy-in among the community of peers to make sure rules are kept.</p>
<p>Based on the survey results, <a href="https://www.catalogueoflife.org/">the Catalogue of Life</a> – the group that has the most comprehensive global species list to date, and the one we’re involved in – is piloting ways of measuring the quality of the lists that make up their catalogue. </p>
<p>These are being trialled first with the creators of lists, everything from viruses to mammals. Then, they will be tested with the taxonomic community at large for further feedback.</p>
<p>Good taxonomy is far more valuable than people realise. One recent study in Australia found that, for every dollar spent on taxonomy, <a href="https://www.science.org.au/support/analysis/decadal-plans-science/discovering-biodiversity-decadal-plan-taxonomy#report2021">the economy gained A$35</a>. The value of taxonomy globally is likely to be colossal.</p>
<p>But the value will be higher still if everyone the world over is able to use the same list of species.</p>
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Read more:
<a href="https://theconversation.com/scientists-re-counted-australias-extinct-species-and-the-result-is-devastating-127611">Scientists re-counted Australia's extinct species, and the result is devastating</a>
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<img src="https://counter.theconversation.com/content/216006/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stephen Garnett receives funding from the Australian Research Council for a project on taxonomic list governance and coordinates the Catalogue of Life Working Group on Taxonomic Lists. </span></em></p><p class="fine-print"><em><span>Aaron M. Lien is a member of the Catalogue of Life Working Group on Taxonomic Lists and the Global Species List Working Group. </span></em></p>Only after a species is identified and listed by taxonomists can it be protected. Yet we still don’t have one globally agreed-upon list of every species. A new 74-nation survey points to the solution.Stephen Garnett, Professor of Conservation and Sustainable Livelihoods, Charles Darwin UniversityAaron M. Lien, Assistant Professor of Ecology, Management and Restoration of Rangelands, University of ArizonaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2123082023-10-17T15:29:28Z2023-10-17T15:29:28ZHow animal traits have shaped the journey of species across the globe<p>The devastating <a href="https://www.ngdc.noaa.gov/hazel/view/hazards/tsunami/event-more-info/5413">tsunami</a> that hit Japan in March 2011 set off a series of events which have long fascinated scientists like me. It was so powerful that it caused 5 million tonnes of debris to <a href="https://marinedebris.noaa.gov/japan-tsunami-marine-debris/monitoring-tsunami-debris-north-american-shorelines">wash</a> into the Pacific – 1.5 million tonnes remained afloat and started drifting with the currents. </p>
<p>One year later, and half a world away, debris began washing ashore on the west coast of North America. More than 280 Japanese coastal species such as mussels, barnacles and even some species of fish, had <a href="https://www.science.org/doi/full/10.1126/science.aao1498?casa_token=YwHfCNElf14AAAAA:zJj4eY3uUm2_m4ZH5YzIO6ecvSWdVa_53yZk0ycnxm1Ga3bPLTl5Z6hCbUhvsmA4d0KSPHFPKz84nQ">hitched a ride</a> on the debris and made an incredible journey across the ocean. These species were still alive and had the potential to establish new populations. </p>
<p>How animals cross major barriers, such as oceans and mountain ranges, to shape Earth’s biodiversity is an intriguing topic. And a new <a href="https://www.nature.com/articles/s41559-023-02150-5">study</a> by my collaborators and I has shed light on this process, revealing how animal characteristics such as body size and life history can influence their spread across the globe.</p>
<p>We know that such dispersal events occur in terrestrial species as well. For instance, at least 15 green iguanas <a href="https://www.nature.com/articles/26886">journeyed</a> more than 200km (124 miles) from Guadeloupe to Anguilla in the Caribbean in 1995. They arrived on a mat of logs and trees (likely uprooted through a hurricane), some of which were more than 9 metres (20 feet) long. </p>
<h2>The role of animal characteristics in dispersal</h2>
<p>When animals move across major barriers it can have a big impact on both the new and old locations. For example, an invasive species can arrive in a new area and compete with native species for resources. However, those consequences can be even greater over longer periods of time.</p>
<p>The movement of monkeys from Africa to South America around 35 million years ago led to the evolution of more than 90 species of <a href="https://www.annualreviews.org/doi/abs/10.1146/annurev-anthro-102116-041510?casa_token=CZtEoQ5Z9bMAAAAA%3AX9JrgVyGxxegDXgVTUPNHZboMldBec1egagn5S4pLwx4yudreF4L6Q6zG4jUeB9tMxJEIy4q67iX&journalCode=anthro">New World monkeys</a>, including tamarins, capuchins and spider monkeys. And a few chameleons rafting on vegetation from Africa to Madagascar is why we find half of all living <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2013.0184">chameleon</a> species there today.</p>
<p>These events were long thought to be determined by chance – the coincidence of some chameleons sitting on the right tree at the right time. However, <a href="https://www.jstor.org/stable/pdf/24529638.pdf?casa_token=NyxiUsFXod0AAAAA:9aBvrCPO0om98AjWOfs482QWf5eQxRUwKt95p4S3trPy1CQ2CM4K0AJeMBtsNKwKST8ILswcwdjQBRq8ZpdR5-3KL3gOn9uYZHOjzDdPyTm4R3Dom1o">some scientists</a> have suggested there might be more to it. They hypothesised there could be more general patterns in the animals that reach their destination successfully, related to certain characteristics.</p>
<p>Could body size affect how far a species can travel? Animals with more fat reserves may be able to travel longer distances. Or could it be how a species reproduces and survives? For example, animals that lay many eggs or mature early may be more likely to establish a new population in a new place.</p>
<p>But despite a vigorous theoretical debate, the options to test these hypotheses were limited because such dispersal events are rare. Also, the right statistical tools were not available until recently.</p>
<p>Thanks to the recent development of new <a href="https://academic.oup.com/sysbio/article/69/1/61/5490843">biogeographical models</a> and the great availability of data, we can now try to answer questions about how tetrapod species (amphibians, reptiles, birds and mammals) have moved around the globe over the past 300 million years and whether successful species share any common characteristics.</p>
<p>These models allow us to estimate the movements of species’ ancestors while also considering their characteristics. We used these models to study 7,009 species belonging to 56 groups of tetrapods.</p>
<h2>What we found</h2>
<p>For 91% of the animal groups we studied, models that included species characteristics were better supported than models that didn’t. This means that body size and life history are closely linked to how successful a species is at moving to and establishing itself in a new location.</p>
<p>Animals with large bodies and fast life histories (breeding early and often, like water voles) generally dispersed more successfully, as expected. However, there were some exceptions to this rule. In some groups, smaller animals or animals with average traits had higher dispersal rates.</p>
<p>For example, small hummingbirds dispersed better than larger ones, and poison dart frogs with intermediate life histories dispersed better than those with very fast or very slow life histories.</p>
<p>We investigated this variation further and found that the relationship between body size and movement depended on the average size and life history of the group. Our results show that the links between characteristics and dispersal success depend on both body size and life history, and that these cannot be considered separately. </p>
<p>Groups in which small size was an advantage were often already made up of small species (making the dispersal-prone species even smaller), and these species also had fast life histories. We found this to be true for the rodent families <a href="https://www.britannica.com/animal/Muridae"><em>Muridae</em></a> and <a href="https://nhpbs.org/wild/cricetidae.asp"><em>Cricetidae</em></a>. </p>
<p>But groups in which dispersers had intermediate body sizes generally had slow life histories (meaning they had low reproductive output but long lifespans). This means the combination of small body size and slow life history is very unlikely to be an advantage for dispersal across major barriers such as oceans.</p>
<h2>It’s not just chance</h2>
<p>It is amazing to think that rare dispersal events, which can lead to the rise of many new species, are not completely random. Instead, the intrinsic characteristics of species can shape the histories of entire groups of animals, even though chance still may play an important role.</p>
<p>At the same time, two of the most important <a href="https://zenodo.org/record/3553579">environmental challenges</a> of our time are related to movement across major barriers: biological invasions and species’ responses to climate change. On a planet facing rapid changes, understanding how animals move across barriers is therefore crucial.</p><img src="https://counter.theconversation.com/content/212308/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>While working on this study, Sarah-Sophie Weil was affiliated with Université Grenoble Alpes (France) and Swansea University (Wales, UK) who supported her through Initiative d’excellence (IDEX) International Strategic Partnership and Swansea University Strategic Partner Research (SUSPR) scholarships.</span></em></p>New research looks at how different species have managed to cross geographic barriers throughout history and whether their individual traits played a crucial role in these journeys.Sarah-Sophie Weil, PhD candidate, Swansea UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2121082023-08-29T04:26:14Z2023-08-29T04:26:14ZHow a lethal fungus is shrinking living space for our frogs<p>In 1993, frogs were found dying <a href="https://www.pnas.org/doi/full/10.1073/pnas.95.15.9031">en masse</a> in Far North Queensland. When scientists analysed their bodies, they found something weird. Their small bodies were covered in spores. </p>
<p>It was an epidemic. An aquatic fungus had eaten the keratin in their skin, compromising its function and leading to cardiac arrest. And worse, the amphibian chytrid fungus (<em>Batrachochytrium dendrobatidis</em>) had been quietly spreading around the world, from South America to Europe, killing frogs wherever it went. </p>
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<a href="https://images.theconversation.com/files/545151/original/file-20230829-19-2sjqta.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/545151/original/file-20230829-19-2sjqta.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/545151/original/file-20230829-19-2sjqta.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=481&fit=crop&dpr=1 600w, https://images.theconversation.com/files/545151/original/file-20230829-19-2sjqta.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=481&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/545151/original/file-20230829-19-2sjqta.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=481&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/545151/original/file-20230829-19-2sjqta.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=605&fit=crop&dpr=1 754w, https://images.theconversation.com/files/545151/original/file-20230829-19-2sjqta.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=605&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/545151/original/file-20230829-19-2sjqta.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=605&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">It doesn’t look lethal – but looks can be deceiving. This is a chytrid zoosporangium, which will release zoospores that propel themselves through water in search of amphibian hosts.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Batrachochytrium_dendrobatidis#/media/File:CSIRO_ScienceImage_1392_Scanning_Electron_Micrograph_of_Chytrid_Fungus.jpg">CSIRO/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<p>Likely native to the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6311102/">Korean Peninsula</a>, it was first detected in Australia in the <a href="https://www.sciencedirect.com/science/article/pii/S0006320716310126">late 1970s</a>. As it spread, it <a href="https://www.sciencedirect.com/science/article/pii/S0006320716310126">caused the extinction</a> of at least four Australian frog species and probably three others. </p>
<p>This lethal pathogen is a selective killer. As our <a href="https://www.nature.com/articles/s41559-023-02155-0">new research</a> shows, it effectively makes some areas a no-go zone for susceptible frog species. The fungus doesn’t like hot conditions. But in cooler environments – such as in southern Australia and higher up in mountain ranges – it flourishes. Mortality rates in these environments can approach 100% for some frog species. </p>
<h2>Pushed from the highlands</h2>
<p>Australia is rich in frogs, with 247 surviving species at last count. Most are endemic to the continent – and many are spectacularly beautiful or, like the <a href="https://www.theguardian.com/culture/2022/feb/21/the-15-most-interesting-australian-frogs-sorted">turtle frog</a>, bizarre. </p>
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<a href="https://images.theconversation.com/files/545161/original/file-20230829-30-f0vm7l.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="turtle frog" src="https://images.theconversation.com/files/545161/original/file-20230829-30-f0vm7l.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/545161/original/file-20230829-30-f0vm7l.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/545161/original/file-20230829-30-f0vm7l.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/545161/original/file-20230829-30-f0vm7l.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/545161/original/file-20230829-30-f0vm7l.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/545161/original/file-20230829-30-f0vm7l.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/545161/original/file-20230829-30-f0vm7l.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The turtle frog (Myobatrachus gouldii) is one of Australia’s strangest.</span>
<span class="attribution"><span class="source">Stephen Zozaya/Wikimedia</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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</figure>
<p>The gorgeous Australian lace-lid treefrog was once widespread across the rainforests of Queensland’s Wet Tropics, which run from Townsville to Cooktown, stretching from sea level up to Queensland’s highest mountain, the 1,622 metre Mt Bartle Frere. </p>
<p>Lace-lid treefrogs once lived throughout these forests, whether on mountains or down near sea level. But they have been driven from rainforests above 400 metres. Down lower, the heat makes it harder for chytrid to kill, and the frog’s higher breeding rate can outpace deaths from the disease. </p>
<h2>No-go zones</h2>
<p>Australians know full well about the damage introduced species can do. Cane toads kill native predators like quolls who aren’t used to their toxin. Cats and foxes have driven many small mammals to extinction. </p>
<p>But even when a species survives contact with an introduced species, it can be forever changed. </p>
<p>That’s because of less visible effects introduced species like chytrid fungus can have, such as shrinking the areas where native species can survive. When this happens, our species can be pushed into smaller parts of their original range, known as environmental refuges. </p>
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Read more:
<a href="https://theconversation.com/the-worlds-worst-animal-disease-is-killing-frogs-worldwide-a-testing-breakthrough-could-help-save-them-205872">The world's worst animal disease is killing frogs worldwide. A testing breakthrough could help save them</a>
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<p>As our research shows, it’s not just geographic range that changes. It also changes their niche – the set of environmental conditions where species can survive. Introduced species can actually force much larger contractions to a native species’ niche than to its geographic range. </p>
<p>You might wonder how that can be. It’s because the damage done by introduced species can vary a lot depending on the environment. Introduced species have their own niche – climates and environments where they thrive, and areas where they don’t. </p>
<p>Frog species that survived the initial epidemics don’t just persist in random parts of their old range. Hotter, wetter areas or those with less temperature variability become refuges. Chytrid is still widespread here, but it’s less lethal. </p>
<p>Part of the puzzle is also the fact these refuge areas are naturally easier places for frogs to survive and reproduce. Where populations thrive, they have greater resilience and stand a better chance of surviving the fungus. </p>
<h2>Pushed into refuges</h2>
<p>The pattern we document isn’t just seen in frogs. Researchers suspect similar changes have been forced on many native species impacted by introduced species. </p>
<p>Consider the bush-stone curlew – a long-legged, endearing bird with eerie <a href="https://www.youtube.com/watch?v=gqZsdBF-eKg&ab_channel=Janegrowsgardenrooms">night cries</a>. Many of us will have seen them haunting parks and beer gardens across northern Australia. But the same bird is now extinct or critically endangered in southern Australia, where it used to roam. Why? </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/545164/original/file-20230829-15-qleqn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="bush-stone curlew" src="https://images.theconversation.com/files/545164/original/file-20230829-15-qleqn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/545164/original/file-20230829-15-qleqn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/545164/original/file-20230829-15-qleqn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/545164/original/file-20230829-15-qleqn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/545164/original/file-20230829-15-qleqn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/545164/original/file-20230829-15-qleqn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/545164/original/file-20230829-15-qleqn.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>
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<span class="caption">Bush-stone curlews are lanky, unusual birds with a distinctive call.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<p>Habitat loss has played a role, but this species is <a href="https://www.publish.csiro.au/mu/mu02029">highly susceptible</a> to foxes. Foxes don’t much like the humidity of tropical and subtropical Australia. As a result, the curlew has been pushed out of the drier parts of its niche. </p>
<p>Niche contractions due to introduced species are likely to be widespread but little-studied. </p>
<p>If a species has a shrinking niche, it may change where conservationists direct their efforts. To give threatened species the best chance of survival, we might have to direct our energies to safeguarding them in their environmental refuges, safe from introduced predators or diseases.</p>
<p>When scientists assess how a species is going, we often look at changes in geographic range to gauge the level of risk to the species, from vulnerable through to extinct in the wild. </p>
<p>But this can have limitations. What our work has shown is that the survivable niche for species can shrink much more than its geographic range, reducing resilience to new environmental challenges. If frog species are forced out of upland areas, they may be at more risk from climate change, given higher elevations are likely to be <a href="https://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/eap.1824">most resilient</a> to climate change. </p>
<p>There’s a silver lining here, though. Species can be more resilient than we assume in the face of new threats. Some populations may be hard hit, while others escape. Understanding why that is will be key to give our native species the best chance of surviving an uncertain future. </p>
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Read more:
<a href="https://theconversation.com/a-deadly-disease-has-driven-7-australian-frogs-to-extinction-but-this-endangered-frog-is-fighting-back-189491">A deadly disease has driven 7 Australian frogs to extinction – but this endangered frog is fighting back</a>
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<img src="https://counter.theconversation.com/content/212108/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Geoffrey Heard is a member of the Terrestrial Ecosystem Research Network at the University of Queensland, which is funded under the National Collaborative Research Infrastructure Strategy (NCRIS). The Threatened Species Index, of which Geoffrey Heard is a Science Advisor, has received co-funding from the Department of Climate Change, Energy, the Environment and Water of the Australian Government.</span></em></p><p class="fine-print"><em><span>Benjamin Scheele receives funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Conrad Hoskin receives funding from the Department of Environment and Science (Queensland Government) and the Australian Research Council (ARC). He is affiliated with the College of Science and Engineering, James Cook University (Townsville, Australia).</span></em></p><p class="fine-print"><em><span>Jarrod Sopniewski is supported by a Hackett Postgraduate Research Scholarship at the University of Western Australia.</span></em></p><p class="fine-print"><em><span>Jodi Rowley has received funding from the Department of Agriculture, Water and the Environment, the Australian Museum Foundation and other state, federal and philanthropic agencies.</span></em></p>Introduced species and diseases can drive native species into smaller environmental niches – and that could mean change to how we work to conserve them.Geoffrey Heard, Research fellow, Australian National University and, The University of QueenslandBenjamin Scheele, Research Fellow in Ecology, Australian National UniversityConrad Hoskin, Senior Lecturer, College of Science & Engineering, James Cook UniversityJarrod Sopniewski, PhD student, The University of Western AustraliaJodi Rowley, Curator, Amphibian & Reptile Conservation Biology, Australian Museum, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2069072023-06-26T16:14:05Z2023-06-26T16:14:05ZDog detectives can sniff out protected great crested newts and reduce costly construction delays<p>Construction projects often find themselves at odds with the <a href="https://www.wildlifetrusts.org/wildlife-explorer/amphibians/great-crested-newt">great crested newt</a>. In 2020, the then UK prime minister, Boris Johnson, referred to them as a <a href="https://www.bbc.co.uk/news/uk-politics-53276461">drag on the economy</a>, citing their presence on development sites as a cause for costly delays. These creatures even <a href="https://www.telegraph.co.uk/news/2018/06/11/ed-sheeran-launches-hunt-great-crested-newts-objections-plan/">put a stop</a> to Ed Sheeran’s proposal to build a wedding chapel on his Suffolk estate.</p>
<p>Great crested newts play crucial ecological roles. They breed in ponds and ditches during the spring and early summer, before emerging to spend most of their time on land. This behaviour means they are able to recycle nutrients from water to land.</p>
<p>They are also an important part of the food chain. These newts eat small invertebrates and are prey for many species of reptile, mammal and bird. </p>
<p>But great crested newt populations are dwindling due to the widespread loss of suitable habitat, changes in farming practices and climate change. There are now only 478,000 ponds remaining in the UK’s countryside – a <a href="https://freshwaterhabitats.org.uk/news/great-crested-newt-habitat-report/">50% decline compared to a century ago</a> – and only 20% of the remaining ponds are suitable for breeding great crested newts. </p>
<p>So it’s no surprise that harming these creatures or their habitats <a href="https://www.gov.uk/guidance/great-crested-newts-protection-surveys-and-licences#:%7E:text=Great%20crested%20newts%20are%20a,places%20are%20protected%20by%20law.">is now illegal</a>. Developments that may harm great crested newts can proceed only if suitable new habitats are made for them. </p>
<p>But the current methods for relocating newts, which include the installation of drift fencing, pitfall traps (sunken buckets in the ground) and searching by hand, are time-consuming, restricted to certain seasons, expensive and are often hampered by the weather. Great crested newts also tend to hide underground in mammal burrows and other inaccessible refuges, where they are hard to locate. </p>
<p>However, my colleagues and I <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0285084">have discovered</a> that detection dogs can be a valuable addition to the existing toolkit for managing great crested newt populations. </p>
<p>A trained English springer spaniel, called Freya, was highly accurate at detecting great crested newts, even at distances of up to 2 metres above the ground (87% accuracy) and through 20cm of soil (88% accuracy). This approach offers a non-invasive method for locating this species in inaccessible underground shelters.</p>
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<img alt="A female great crested newt." src="https://images.theconversation.com/files/533471/original/file-20230622-21-sxlihp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/533471/original/file-20230622-21-sxlihp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/533471/original/file-20230622-21-sxlihp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/533471/original/file-20230622-21-sxlihp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/533471/original/file-20230622-21-sxlihp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/533471/original/file-20230622-21-sxlihp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/533471/original/file-20230622-21-sxlihp.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">
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<span class="caption">Great crested newts have a reputation for holding up construction projects.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/greatcrested-newt-triturus-cristatus-single-female-168592301">Erni/Shutterstock</a></span>
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<h2>Dog detectives</h2>
<p>Over 128 trial runs, we conducted experiments to investigate the impact of various distances between target newts and Freya on her ability to locate them. We also tested how well Freya could detect the newts through two different soil types: clay and sand. In some instances, we placed a vent within the soil to mimic a mammal burrow. </p>
<p>Freya accurately located all individual great crested newts across the entire range of tested distances (0.25 metres–2 metres). When Freya detected the smell of a great crested newt, she would lie down and point at where the scent was emerging from. </p>
<p>Freya could locate individual newts both in soils with and without vents. But she was significantly faster and more accurate at detecting newts under clay soil compared to sand. This finding contrasts with previous research that found dogs were able to <a href="https://www.researchgate.net/publication/299522945_The_Effects_of_Soil_Texture_on_the_Ability_of_Human_Remains_Detection_Dogs_to_Detect_Buried_Human_Remains">detect human remains</a> under sandy soil much faster and more accurately than in clay soil. </p>
<p>Our results are likely to do with the type of odour that is emitted and how it reacts with the soil. Great crested newts are amphibians and use moisture to transport pheromones (a chemical that is secreted into the environment to attract a mate for breeding) during their aquatic life phase. The presence of moisture within clay soil may transport their odour to the surface more readily than in sandy soil.</p>
<p>We also found that air temperature influenced how quickly and accurately Freya could detect the newts. Moisture will evaporate at the surface when it’s hot, making it harder for dogs to locate the scent.</p>
<h2>Not so fast</h2>
<p>Using detection dogs to locate great crested newts underground offers valuable insights into the habitat that newts prefer. It also serves practical purposes. Finding and relocating newts is costly and time-consuming at present, but a legal requirement prior to construction activities.</p>
<p>Our findings provide a better understanding of the factors, such as temperature and soil type, that can hinder or improve the chance of detecting these newts. But they also highlight the need for detection dog handlers to be aware of their environmental surroundings and how these factors may impact the dispersal of the newts’ odour.</p>
<p>Furthermore, training dogs and handlers to find great crested newts takes a long time. In fact, it can take up to two years for a dog and its handler to become operational. </p>
<p>This is due to the complexity of the newts’ lifecycle. Great crested newts spend time both above and below the ground, as well as in inaccessible underground hiding places. As a result, the dogs must be exposed to all different types of scenarios during training to ensure they can accurately distinguish between a scent that is accessible above the ground, and a more diluted scent at a distance. </p>
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<img alt="Freya the spaniel and her handler being trained." src="https://images.theconversation.com/files/534003/original/file-20230626-23-2smybj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534003/original/file-20230626-23-2smybj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534003/original/file-20230626-23-2smybj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534003/original/file-20230626-23-2smybj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534003/original/file-20230626-23-2smybj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534003/original/file-20230626-23-2smybj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534003/original/file-20230626-23-2smybj.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">
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<span class="caption">It can take up to two years to train a dog and its handler to detect great crested newts.</span>
<span class="attribution"><span class="source">Nick Upton/Wessex Water</span>, <span class="license">Author provided</span></span>
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<p>Using detection dogs to locate hidden great crested newts has the potential to protect this rare species and reduce costly construction delays. But the complexity of the newts’ life phases and the time-consuming training process for dogs and handlers means it will take time before this effective new method becomes commonplace.</p><img src="https://counter.theconversation.com/content/206907/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nikki Glover 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>Great crested newts cause expensive delays to construction – trained sniffer dogs may offer a solution.Nikki Glover, PhD Candidate in Environmental Biology, University of SalfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2058722023-05-23T20:11:17Z2023-05-23T20:11:17ZThe world’s worst animal disease is killing frogs worldwide. A testing breakthrough could help save them<figure><img src="https://images.theconversation.com/files/527431/original/file-20230522-29-ir3vv6.jpg?ixlib=rb-1.1.0&rect=56%2C568%2C7529%2C4822&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/EP_OHkgn1JI">Jack Hamilton/Unsplash</a></span></figcaption></figure><p>For the past 40 years, a devastating fungal disease has been ravaging frog populations around the world, wiping out 90 species. Unlike the global COVID-19 pandemic, you may not even be aware of this “panzootic” – a pandemic in the animal world. Yet it’s the world’s worst wildlife disease. </p>
<p>Recently published in the journal <a href="https://doi.org/10.1155/2023/9980566">Transboundary and Emerging Diseases</a>, a multinational study has now developed a method to detect all known strains of this disease, caused by the amphibian chytrid fungus. This breakthrough will advance our ability to detect and research this disease, working towards a widely available cure.</p>
<h2>An extreme mortality rate</h2>
<p><a href="https://www.science.org/doi/10.1126/science.aav0379">Chytridiomycosis</a>, or “chytrid” for short, has driven severe declines in over 500 frog species and caused 90 extinctions, including seven in Australia. </p>
<p>The extreme rate of mortality, and the high number of species affected, makes chytrid unequivocally <a href="https://www.science.org/doi/10.1126/science.aav0379">the deadliest animal disease known to date</a>.</p>
<p>Chytrid infects frogs by reproducing in their skin. The single-celled fungus enters a skin cell, multiplies, then breaks back out onto the surface of the animal. This damage to the skin affects the frog’s ability to balance water and salt levels, and eventually leads to death if infection levels are high enough.</p>
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Read more:
<a href="https://theconversation.com/before-the-last-of-us-i-was-part-of-an-international-team-to-chart-the-threat-of-killer-fungi-this-is-what-we-found-199593">Before The Last of Us, I was part of an international team to chart the threat of killer fungi. This is what we found</a>
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<p>Chytrid <a href="https://www.science.org/doi/10.1126/science.aar1965">originated</a> in Asia. It’s believed that global travel and trade in amphibians led to the disease being unwittingly spread to other continents.</p>
<p>Frogs in regions such as Australia and the Americas did not have the evolutionary history with chytrid that could grant them resistance. So, when they were exposed to this new pathogen, the results were devastating.</p>
<p>Many species’ immune systems were simply not equipped to defend against the disease, and mass mortalities ensued. In the 1980s, amphibian biologists began to notice sharp population declines, and in 1998, the chytrid fungal pathogen was finally <a href="https://www.pnas.org/doi/abs/10.1073/pnas.95.15.9031">recognised as the culprit</a>.</p>
<p>Since then, much research has focused on infection trends and how to protect vulnerable frog species. To track such trends, we need a reliable way to detect chytrid in the first place.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/527464/original/file-20230522-27-xc87e7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A dead white frog floating in water with the belly up and legs splayed" src="https://images.theconversation.com/files/527464/original/file-20230522-27-xc87e7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/527464/original/file-20230522-27-xc87e7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/527464/original/file-20230522-27-xc87e7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/527464/original/file-20230522-27-xc87e7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/527464/original/file-20230522-27-xc87e7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/527464/original/file-20230522-27-xc87e7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/527464/original/file-20230522-27-xc87e7.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"></a>
<figcaption>
<span class="caption">Chytrid infections have an extremely high mortality rate, decimating not just entire populations, but even entire species of frog.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/dead-frog-floating-on-water-2282145547">Shutterstock</a></span>
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<h2>An imperfect swab</h2>
<p>To find out if a frog is carrying chytrid, researchers swab the animal and run the same type of test you might recognise from COVID-19 testing – a qPCR. It stands for quantitative polymerase chain reaction, and simply put, is a way to measure the volume of DNA from a species of interest. The test <a href="https://doi.org/10.1073/pnas.95.15.9031">was developed at CSIRO in 2004</a>; unlike a COVID test, however, scientists swab the frog’s skin, not the nose.</p>
<p>Because this test was developed from chytrid in Australia, decades after the pathogen’s arrival in the country, a divergence between the Australian and Asian strains meant this test could not detect chytrid in its region of origin. This has been a major limitation to the past two decades of chytrid research.</p>
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Read more:
<a href="https://theconversation.com/vaccinating-frogs-may-or-may-not-protect-them-against-a-pandemic-but-it-does-provide-another-option-for-conservation-194231">'Vaccinating' frogs may or may not protect them against a pandemic – but it does provide another option for conservation</a>
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<p>Over the past several years, a team led by researchers at the Council of Scientific and Industrial Research – Centre for Cellular and Molecular Biology in India has been working on a new qPCR test that can detect strains of chytrid from Asia. In collaboration with researchers in Australia and Panama, we have now verified the new test also reliably detects chytrid in these countries.</p>
<p>Furthermore, the test can detect another closely related species of chytrid that infects salamanders. The test is also more sensitive, meaning it can detect very low infection levels – thereby broadening the scope of species we can study. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/527465/original/file-20230522-23-88olmq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A black and yellow salamander swimming in clear creek water" src="https://images.theconversation.com/files/527465/original/file-20230522-23-88olmq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/527465/original/file-20230522-23-88olmq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/527465/original/file-20230522-23-88olmq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/527465/original/file-20230522-23-88olmq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/527465/original/file-20230522-23-88olmq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=425&fit=crop&dpr=1 754w, https://images.theconversation.com/files/527465/original/file-20230522-23-88olmq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=425&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/527465/original/file-20230522-23-88olmq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=425&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Salamanders are another group of animals at risk of widespread chytrid fungal disease.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/beautiful-lizard-fire-salamander-water-spring-1651663024">Shutterstock</a></span>
</figcaption>
</figure>
<h2>Natural immunity?</h2>
<p>The most puzzling thing about chytrid is that some amphibian species – even those that have not evolved with the pathogen – don’t become sick when they carry the fungus. These species have some form of natural immune resistance.</p>
<p>However, <a href="https://doi.org/10.1093/icb/icr095">frog immunity</a> is extremely complex. Immunity might come from anti-microbial chemicals within the skin, symbiotic bacteria on the skin, white blood cells and antibodies in the blood, or combinations of these mechanisms.</p>
<p>So far, no clear trend has been found between resistance and immune function. To make matters more complicated, there is also evidence chytrid can suppress a host’s immune response. </p>
<p>Because there haven’t been any observed chytrid declines in Asia, and because detecting chytrid in Asia has been difficult, Asia is lagging behind the rest of the world in chytrid research. Yet the new qPCR test detected high levels of chytrid in a range of amphibian species across India.</p>
<p>Having the ability to study chytrid in its region of origin may help us understand how Asian species evolved resistance – research that may hold a key to help researchers develop a cure for those species in Australia, North and South America, and Europe that are now on the brink. </p>
<p>While the new qPCR test was successful at detecting chytrid in samples from India, Australia, and Panama, we will need to validate and promote the method so it becomes the new gold standard for chytrid testing. Future work will involve using the test to analyse samples from Europe, and samples from Brazil where genetic studies show that chytrid has diverged.</p>
<p>In time, this new way to detect chytrid could be the first step in helping to save frogs – the hidden gems of our forests and wetlands.</p><img src="https://counter.theconversation.com/content/205872/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kaya Klop-Toker received funding from the Australian Academy of Science. </span></em></p><p class="fine-print"><em><span>Karthikeyan Vasudevan receives funding from Council for Scientific and Industrial Research, India. </span></em></p>The chytrid fungal disease has been decimating frog populations worldwide for decades, and research progress has been slow. A new method for detecting the disease could help change its course.Kaya Klop-Toker, Conservation Biology Researcher, University of NewcastleKarthikeyan Vasudevan, Chief Scientist, CSIR - Centre for Cellular & Molecular BiologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1952192023-01-26T13:32:06Z2023-01-26T13:32:06ZIt’ll take 150 years to map Africa’s biodiversity at the current rate. We can’t protect what we don’t know<figure><img src="https://images.theconversation.com/files/504614/original/file-20230116-12-2bq5kf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Niassa Special Reserve in Northern Mozambique's is just one of the continent's under-mapped biodiversity areas. </span> <span class="attribution"><span class="source">Harith Omar Morgadinho Farooq</span></span></figcaption></figure><p>The African continent is bursting with biodiversity. In <a href="https://www.cbd.int/gbo/gbo4/outlook-africa-en.pdf">a 2016 report</a>, the United Nations Environment Programme wrote:</p>
<blockquote>
<p>Africa’s biomes extend from mangroves to deserts, from Mediterranean to tropical forests, from temperate to sub-tropical and montane grasslands and savannas, and even to ice-capped mountains.</p>
</blockquote>
<p>About a quarter of the world’s species of plants and animals are found on the continent. </p>
<p>But biodiversity isn’t just beautiful. We need it to survive. Different species and biomes provide ecosystem services to humans: food, clothing, potable water and the very air we breathe. The disappearance of a seemingly unimportant animal, like a certain species of bee, may result in the extinction of certain plant species. That, in turn, affects humans and other species.</p>
<p><a href="https://theconversation.com/cop15-biodiversity-summit-in-montreal-canada-failed-to-meet-its-2020-conservation-targets-will-2030-be-any-better-195347">Experts have estimated</a> that each country, globally, must protect the biodiversity of 30% of its territory by 2030 to at least mitigate the effects of ongoing environmental damage.</p>
<p>But we found in <a href="https://academic.oup.com/sysbio/article/70/3/623/6030962">a recent study</a> that huge swathes of Africa remain unstudied and their species undocumented. Why? Because scientists keep returning to areas whose biodiversity has already been mapped, rather than visiting new, unexplored areas. </p>
<p>We show that at the current rate of discovery it may take more than 150 years to visit every 100km x 100km area in Africa even once. And, our analysis suggests, one visit won’t be enough. It may take up to 27 field expeditions to document just 50% of an area’s existing species.</p>
<p>If scientists don’t start venturing outside well-mapped areas, thousands of new species will remain undocumented. Adequate data is crucial to identifying and delineating species boundaries, understanding spatial biodiversity patterns and effectively promoting species conservation. We cannot protect what we don’t know. </p>
<h2>Assessing the data</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/505539/original/file-20230120-14-j71362.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/505539/original/file-20230120-14-j71362.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=225&fit=crop&dpr=1 600w, https://images.theconversation.com/files/505539/original/file-20230120-14-j71362.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=225&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/505539/original/file-20230120-14-j71362.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=225&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/505539/original/file-20230120-14-j71362.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=283&fit=crop&dpr=1 754w, https://images.theconversation.com/files/505539/original/file-20230120-14-j71362.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=283&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/505539/original/file-20230120-14-j71362.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=283&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">All of the uncoloured areas on these maps of Africa show parts of the continent where the study didn’t find any scientific expeditions.</span>
<span class="attribution"><span class="source">Authors supplied</span></span>
</figcaption>
</figure>
<p>Our estimates are based only on birds, mammals and amphibians — three well-studied groups. The knowledge bias and spatial patterns we report are likely to be considerably worse for other already under-described groups such as <a href="https://www.pnas.org/doi/10.1073/pnas.1110319108">plants</a>, <a href="https://apsjournals.apsnet.org/doi/10.1094/PHYTO.1997.87.9.888">fungi</a> and <a href="http://ecologylabs.org/wp-content/uploads/2018/03/Estimate-of-insect-species.pdf">insects</a>. </p>
<p>We wanted to use data to produce visuals of the continent’s unstudied or under-studied areas. Usually when scientists go to the field, they collect specimens which end up in museums and then show up on the museums’ databases. These databases have been aggregated into one by the <a href="https://www.gbif.org/">Global Biodiversity Information Facility</a>, so all the data sets can be accessed at once.</p>
<p>This was the source of our data and meant we were counting scientific expeditions, a better representation of species mapping than, for instance, researchers’ anecdotes or a random sample of journal articles.</p>
<p>To estimate the number of expeditions in each 100km x 100km grid cell in Africa, a standard method for conducting analyses of this sort, we counted the number of years which had at least one collection involving either amphibians, mammals or birds. So, a value of five, for instance, shows that there were collections made by scientists in five different years. </p>
<p>Then we applied statistical tools that use the current rate to model the future trend <em>if</em> the behaviour (the rate of expeditions) stays the same. </p>
<p>Our results emphasise that current practice is insufficient to adequately classify and map African biodiversity. This can result in misleading and self-reinforcing conservation priorities: areas are considered to be of high conservation value largely because they are better surveyed rather than because they are actually more diverse. </p>
<h2>Pushing for change</h2>
<p>There are ways to improve this situation. </p>
<p>Agencies, companies and philanthropists that fund research should actively promote projects that aim to sample areas where baseline biodiversity data is lacking.</p>
<p>Researchers should, meanwhile, increase the taxonomic and methodological scope of their collection efforts. Given the logistical and legislative challenges of carrying out fieldwork across most of Africa, we urge scientists to collaborate with specialists in different institutions and with varied taxonomic expertise to responsibly sample the maximum possible number of taxa – in full or as tissue samples, especially for endangered or large species.</p>
<p>There’s also a need for scientists to engage with each other beyond borders. Biological sampling in Africa has, to <a href="https://esajournals.onlinelibrary.wiley.com/doi/10.1890/110154">a large extent</a>, <a href="https://onlinelibrary.wiley.com/doi/10.1111/ecog.05926">been carried out</a> by European and North American institutions. Researchers from institutions in those regions need to collaborate with local universities, rather than just using locals as field assistants.</p>
<p>At a government level, the process for sampling permits should be made transparent and available online for every country in the continent, to encourage and streamline biodiversity research.</p><img src="https://counter.theconversation.com/content/195219/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>Huge swathes of Africa remain unstudied and their species undocumented.Harith Omar Morgadinho Farooq, Post-doc, University of CopenhagenSøren Faurby, Senior Lecturer in Zoology, University of GothenburgLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1942312022-12-16T19:21:22Z2022-12-16T19:21:22Z‘Vaccinating’ frogs may or may not protect them against a pandemic – but it does provide another option for conservation<figure><img src="https://images.theconversation.com/files/501430/original/file-20221215-22-xp9m5j.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1280%2C850&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">California red-legged frogs are threatened with extinction.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/4KnwCD">KQED QUEST/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><p>When the COVID-19 pandemic first emerged, many <a href="https://scholar.google.com/citations?user=qnBAFpMAAAAJ&hl=en">wildlife disease researchers like me</a> were not too surprised. Some were intrigued it hadn’t happened sooner; after all, it is our job to observe, describe and study pandemic dynamics in animals.</p>
<p>Amphibians, for example, have been undergoing a global panzootic – the animal version of a pandemic – for decades. In the late 1990s, researchers identified the <a href="https://www.amphibianark.org/the-crisis/chytrid-fungus/">amphibian chytrid fungus</a>, which causes the often-lethal disease <a href="https://doi.org/10.1073/pnas.95.15.9031">chytridiomycosis</a>, as the probable culprit behind frog and salamander declines and extinctions from <a href="https://www.nespthreatenedspecies.edu.au/news-and-media/media-releases/these-frogs-need-our-help-scientists-name-the-australian-frogs-at-greatest-risk-of-extinction-four-likely-already-lost">Australia</a> to <a href="https://www.americanscientist.org/article/lessons-of-the-lost">Central America</a> and elsewhere that began 10, 20 or even <a href="https://doi.org/10.1002/ece3.3468">30 years before</a>.</p>
<p>Scientists have found this pathogen on <a href="https://www.researchgate.net/publication/26645573_Fisher_MC_Garner_TWJ_Walker_SF_Global_emergence_of_Batrachochytrium_dendrobatidis_and_amphibian_Chytridiomycosis_in_space_time_and_host_Ann_Rev_Microbiol_63_291-310">every continent that amphibians inhabit</a>, and the extensive <a href="https://deepblue.lib.umich.edu/bitstream/handle/2027.42/94283/mec5710.pdf;jsessionid=4E641E9F7DC2CEBA5C05B6777315B37A?sequence=1">global amphibian trade</a> has likely spread highly lethal strains around the world. The amphibian chytrid fungus is widespread in some <a href="https://doi.org/10.1371/journal.pone.0222718">geographic regions</a>, and, like the virus that causes COVID-19, it can <a href="https://doi.org/10.1534/g3.115.021808">mutate rapidly</a> and take new forms that cause varying disease severity.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/WpOl_yc8n6Q?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Many amphibians are disappearing around the world.</span></figcaption>
</figure>
<p><a href="https://www.gov.uk/guidance/species-reintroductions-and-other-conservation-translocations">Conservation translocation</a> is an increasingly popular way to recover species that have experienced extensive population declines. It involves moving organisms to reestablish populations that have gone extinct, supplement existing ones or establish new ones in areas where the species was not previously present. However, when the amphibian chytrid fungus is prevalent in the landscape, frogs are likely to get sick again, hampering the success of translocation.</p>
<p>To avoid the setbacks of disease, researchers are <a href="https://ucnrs.org/inoculating-frogs-against-an-amphibian-pandemic/">using a tool</a> often employed against human pandemics: <a href="https://www.kqed.org/science/959844/can-a-new-vaccine-stem-the-frog-apocalypse">inoculations akin to vaccines</a>.</p>
<p>In <a href="https://doi.org/10.1002/ecs2.4294">our recent study</a>, my research team and I inoculated threatened <a href="https://ecos.fws.gov/ecp/species/2891">California red-legged frogs</a> against chytrid fungus before translocation by exposing them to the chytrid fungus in the laboratory. We wanted to see if we could activate their immune systems and give them an advantage over the fungus once they are released. Our results were unexpected.</p>
<h2>Nothing a cocktail won’t cure</h2>
<p>Since 2017, Yosemite National Park has been actively translocating California red-legged frogs to <a href="https://www.nps.gov/yose/learn/news/threatened-california-red-legged-frogs-making-a-comeback-in-yosemite-national-park-after-a-50-year-absence.htm">Yosemite Valley</a>, where the chytrid fungus is already present. We used a <a href="https://doi.org/10.1002/ecs2.4294">small subset</a> of these translocated frogs in our study.</p>
<p>We collected wild frog eggs at a place where the species is thriving, about 100 miles northwest of Yosemite Valley, then raised them in captivity at the San Francisco Zoo. Once they metamorphosed into juvenile frogs, we bathed 20 in a “cocktail” of four live, active strains of the fungus. After three weeks, they were given a bath of an antifungal drug to halt the infection. Another 40 frogs that were not exposed to the fungus were also given a bath of an antifungal drug. </p>
<p>Then we reexposed the 20 previously infected frogs to the fungus a second time, while 20 previously uninfected frogs were exposed to the fungus for the first time. We wanted to see how frogs with a second infection – namely, those that were “vaccinated” – compared with those that were infected only once.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/501438/original/file-20221215-15-uz70p9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Scanning electron micrograph of chytrid fungus" src="https://images.theconversation.com/files/501438/original/file-20221215-15-uz70p9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/501438/original/file-20221215-15-uz70p9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=482&fit=crop&dpr=1 600w, https://images.theconversation.com/files/501438/original/file-20221215-15-uz70p9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=482&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/501438/original/file-20221215-15-uz70p9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=482&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/501438/original/file-20221215-15-uz70p9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=605&fit=crop&dpr=1 754w, https://images.theconversation.com/files/501438/original/file-20221215-15-uz70p9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=605&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/501438/original/file-20221215-15-uz70p9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=605&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 chytrid fungus has devastated frog populations globally.</span>
<span class="attribution"><a class="source" href="https://www.scienceimage.csiro.au/image/1392">Alex Hyatt/CSIRO</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>What we found was surprising: 35% of frogs infected only once successfully cleared the infection without vaccination or an antifungal drug. This suggested that they have some measure of <a href="https://www.ncbi.nlm.nih.gov/books/NBK26846/">innate immunity</a>, meaning their immune system’s first line of defense was able to fight off the fungus. In addition, frogs infected a second time had a 31% overall lower rate of infection than those that were infected only once. This suggested that the vaccinelike treatment also works by stimulating <a href="https://www.ncbi.nlm.nih.gov/books/NBK21070/">adaptive immunity</a>, meaning their immune system learned to recognize the fungus from their first exposure and fight it off more efficiently. None of the frogs died from their fungal infections.</p>
<p>Before releasing them to the wild, we treated the frogs with an antifungal drug and monitored to make sure they were disease-free. We attached tiny transmitters with beaded belts around their waists so we could track their infections and survival over three months.</p>
<p>Unexpectedly, we found no difference in disease burden between the frogs that had never been infected and those that had been previously infected in the laboratory. This suggests that immunizing this species for chytrid fungus, at least in Yosemite, may be unnecessary to ensure their survival after reintroduction.</p>
<p>Indeed, the California red-legged frogs released into Yosemite Valley are thriving three years after our experiment and six years after their first translocation. They are hibernating successfully through the cold winters and emerging early in the spring for reproduction.</p>
<h2>Hope for the future</h2>
<p>Our study takes a new approach to the emerging tool of inoculation against the chytrid fungus. By combining ex situ, or laboratory, experiments with in situ, or in the field, implementation, we put lab observations to the test in the real world. This type of work strengthens collaborations between wildlife managers and zoos, which are increasingly needed as the <a href="https://www.un.org/sustainabledevelopment/blog/2019/05/nature-decline-unprecedented-report/">biodiversity crisis accelerates</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/501435/original/file-20221215-17-59fogl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="California red-legged frog floating in grassy water" src="https://images.theconversation.com/files/501435/original/file-20221215-17-59fogl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/501435/original/file-20221215-17-59fogl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/501435/original/file-20221215-17-59fogl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/501435/original/file-20221215-17-59fogl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/501435/original/file-20221215-17-59fogl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/501435/original/file-20221215-17-59fogl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/501435/original/file-20221215-17-59fogl.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">Preservation efforts for the California red-legged frogs are in progress.</span>
<span class="attribution"><a class="source" href="https://flic.kr/p/aw8gBV">Greg Schechter/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Though California red-legged frogs in Yosemite Valley didn’t seem to need vaccinations, this doesn’t mean that other imperiled amphibian species around the world do not. Research on chytrid inoculations in other species have had mixed results, ranging from <a href="https://doi.org/10.1371/journal.pone.0093356">not improving survival</a> to <a href="https://pubmed.ncbi.nlm.nih.gov/25008531/">reducing infection burden</a> associated with increased survival. One of the primary challenges of this approach to conservation is that even if vaccination increases survival after initial release, this immunity does not carry forward to successive generations.</p>
<p>There is hope, however. Researchers are working to identify the <a href="https://doi.org/10.1111/acv.12459">genetic signatures associated with immunity</a> to the chytrid fungus. If successful, breeding programs can artificially select for – and perhaps even <a href="https://www.sciencedirect.com/science/article/pii/S0169534721003384">gene-edit</a> – protective traits to give frogs a leg up on a pathogen that has devastated amphibian populations worldwide.</p><img src="https://counter.theconversation.com/content/194231/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrea Adams previously received funding from the Yosemite Conservancy for conducting this research as a postdoctoral researcher at Yosemite National Park. Funding for her current academic appointment is received from the U.S. Fish and Wildlife Service.</span></em></p>Amphibians have been devastated by a chytrid fungus pandemic. Researchers immunized California red-legged frogs in Yosemite to give them a fighting chance at survival, with surprising results.Andrea J. Adams, Researcher in Ecology, University of California, Santa BarbaraLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1886802022-09-13T17:43:35Z2022-09-13T17:43:35ZInvasive reptile and amphibian species are causing billions of dollars in damages globally<figure><img src="https://images.theconversation.com/files/482138/original/file-20220831-4764-z2dv88.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Invasive alien species are a growing concern for both the environment and economy.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Economic growth and globalization have connected the world’s most distant places. Rapid trade and transport have boosted economic growth globally, but not without consequences: many species have been introduced to new regions, far from where they evolved.</p>
<p>Alien species are those introduced by humans to regions outside their natural range. Invasive alien species are a growing concern for both the environment and economy. </p>
<p>In recent decades, alien herpetofauna — amphibians and reptiles — have increasingly gained attention on social media, with more information being circulated about the impacts these species have on native flora and fauna. </p>
<p>And yet, the number of invasive reptiles and amphibians is increasing, facilitated by the persistently high globalization of human activities. </p>
<h2>Detrimental effects</h2>
<p>Some invasive species arrive unintentionally as hitchhikers on planes, ships and cars. Others are sold intentionally as exotic pets, which then escape or are released into the wild. Of those that survive and establish, some are able to spread with severe negative impacts, giving them the title of “invasive.” </p>
<p><a href="https://doi.org/10.1016/j.scitotenv.2022.153404">These impacts can be massive</a>. Alien species are a leading cause of biodiversity loss and extinction worldwide, affecting human welfare and quality of life. </p>
<p>While alien species can also have detrimental effects on the economy, this is often complex to assess. Available information is often scattered, covers different scales or periods, recorded using variable measurements and currencies and presented in many languages. </p>
<p>The InvaCost database, <a href="https://doi.org/10.1038/s41597-020-00586-z">the most comprehensive database of the cost of alien species and a global initiative of scientists</a>, gathers this information and makes it accessible to researchers and the public.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/482402/original/file-20220901-9301-wcqbt7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="a Burmese python swimming through shallow water" src="https://images.theconversation.com/files/482402/original/file-20220901-9301-wcqbt7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/482402/original/file-20220901-9301-wcqbt7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/482402/original/file-20220901-9301-wcqbt7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/482402/original/file-20220901-9301-wcqbt7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/482402/original/file-20220901-9301-wcqbt7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/482402/original/file-20220901-9301-wcqbt7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/482402/original/file-20220901-9301-wcqbt7.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 alien Burmese python has successfully established itself in the Everglades National Park in Florida, where it has decimated local mammal populations.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<h2>Surprising impacts</h2>
<p>The most common pathway for invasive reptiles and amphibians is the often-illegal trade of exotic snakes and frogs as pets. </p>
<p>Another common pathway is release for biological control, where a new species is introduced in an attempt to control a pest species. This is how <a href="https://doi.org/10.1111/j.1469-1795.2009.00319.x">the cane toad was introduced in Australia</a>. </p>
<p>Other pathways include aquaculture enterprises, such as those that raise <a href="https://doi.org/10.1007/s10530-007-9178-x">American bullfrogs for human consumption</a> and <a href="https://doi.org/10.2984/1534-6188(2007)61%5B307:BAIOPI%5D2.0.CO;2">species hitchhiking on planes or boats</a>.</p>
<p>Alien reptiles and amphibians can have quite unusual and surprising economic impacts. For instance, after the arrival of the coquí frog to Hawaii via contaminated nursery plants, <a href="https://ageconsearch.umn.edu/record/21313/">its very loud mating song caused severe declines in property values in infested areas</a>.</p>
<p>More typical economic impacts stem from programs for the control or eradication of these species. Management programs are needed due to the damage these invaders cause on biodiversity by eliminating native species, including at-risk amphibians and reptiles.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/481903/original/file-20220830-37919-2ltj1a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An American bullfrog with a large goldfish of approximately equal size in its mouth" src="https://images.theconversation.com/files/481903/original/file-20220830-37919-2ltj1a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/481903/original/file-20220830-37919-2ltj1a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=451&fit=crop&dpr=1 600w, https://images.theconversation.com/files/481903/original/file-20220830-37919-2ltj1a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=451&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/481903/original/file-20220830-37919-2ltj1a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=451&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/481903/original/file-20220830-37919-2ltj1a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/481903/original/file-20220830-37919-2ltj1a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/481903/original/file-20220830-37919-2ltj1a.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"></a>
<figcaption>
<span class="caption">American bullfrogs have the largest reported economic impacts of any amphibian.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Bullfrog_tries_to_swallow_huge_Goldfish_-_Fish_survived.jpg">(Rusty Clark/Wikimedia Commons)</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>This is the case for one of the most famous snakes in the pet trade, the California kingsnake, <a href="https://phys.org/news/2021-12-invasive-snake-gran-canaria-native.html">for which numerous eradication programs on the Canary Islands exist</a>.</p>
<h2>Quantifying the damage</h2>
<p>Our team of researchers quantified and synthesized, for the first time, <a href="https://doi.org/10.1038/s41598-022-15079-9">the economic costs of invasive reptiles and amphibians worldwide using the InvaCost database</a>. Between 1986 and 2020, we found that the cost of invasive reptiles and amphibians was massive, totalling approximately US$17 billion — with US$10.4 billion due to reptiles and US$6.3 billion due to amphibians. </p>
<p>Further, the bulk of these costs was from a small subset of highly impactful species. Most notably, the brown tree snake alone has resulted in a loss of US$4.5 million per year in Guam due to island-wide power outages and costing a total of US$10.34 billion during the study period (1986-2019).</p>
<p>The runner-up in terms of total impacts was the American bullfrog, whose impacts of US$6.04 billion accounted for approximately 97 per cent of the total amphibian cost, mostly due to control and eradication measures in Europe.</p>
<p>The types of costs incurred varied across species. In the case of amphibians, costs mostly originated from government expenditures — US$6.25 billion, or 99.6 per cent. These costs are derived from mitigating the spread or impacts of invaders through prevention, control, research, long-term management or eradication. </p>
<p>Reptile costs, however, mostly affected the public and social welfare sector, reportedly causing staggering damages — US$10.02 billion, or 96.6 per cent. These costs are incurred directly due to the impact of invaders, such as yield loss, infrastructure damage or income reduction.</p>
<p>Geographically, we found that economic impacts were present across all continents, except for amphibians in Africa, likely due to the lack of information. The geographic regions most affected were Europe by amphibians (US$6.04 billion), and Oceania and the Pacific Islands by reptiles (US$10.35 billion, 99.61 per cent).</p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/p/BsR3Q1XgUjH","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<h2>Prevention is the better solution</h2>
<p>The economic costs of herpetofauna invasions are massive across all continents, but also underestimated. The vast part of our estimated total cost originated from only two species: the brown tree snake and the American bullfrog, which is likely, at least in part, due to missing data. </p>
<p>Further, only 21 species (six amphibians and 15 reptiles) were reported in InvaCost, out of 280 alien amphibians and reptiles recorded worldwide. </p>
<p>It should nevertheless be acknowledged that not all invasive reptiles and amphibians will have tangible monetary impacts, so some gaps are expected. Nonetheless, a greater research effort is needed to distinguish the true absence of economic cost from gaps in cost detection — especially for those species known to cause detrimental ecological impacts.</p>
<p>And as shown, investments in preventive measures can be <a href="https://doi.org/10.1016/j.scitotenv.2022.153404">an important money-saving measure for the public over the long term</a>, compared to reactive control approaches once a species has successfully invaded. </p>
<p>We propose the compilation of national lists for species facing import and selling bans, better screening for potentially harmful species and a more comprehensive effort to obtain information on the actual and species-specific costs. Our research highlights the importance of these measures to prevent future immense economic costs.</p><img src="https://counter.theconversation.com/content/188680/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>EJH was funded by a B3X postdoctoral fellowship from the Fonds de Recherche du Québec - Nature et Technologies.</span></em></p><p class="fine-print"><em><span>Ismael Soto Almena 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 since the mid-1980s, the economic impact of invasive reptiles and amphibians totals more than US$17 billion.Ismael Soto Almena, PhD Student, Protection of Waters, University of South BohemiaEmma J. Hudgins, Postdoctoral fellow, Biology, Carleton UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1895192022-09-01T18:04:30Z2022-09-01T18:04:30ZAxolotls can regenerate their brains – these adorable salamanders are helping unlock the mysteries of brain evolution and regeneration<figure><img src="https://images.theconversation.com/files/482164/original/file-20220831-8166-9xe77t.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4096%2C2728&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Axolotls are a model organism researchers use to study a variety of topics in biology.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/aE4bnU">Ruben Undheim/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>The <a href="https://www.nationalgeographic.com/animals/amphibians/facts/axolotl">axolotl</a> (<em>Ambystoma mexicanum</em>) is an aquatic salamander renowned for its ability to <a href="https://doi.org/10.1159%2F000504294">regenerate its spinal cord, heart and limbs</a>. These amphibians also <a href="https://doi.org/10.1186/1749-8104-8-1">readily make new neurons</a> throughout their lives. In 1964, researchers observed that adult axolotls could <a href="https://pubmed.ncbi.nlm.nih.gov/14248567/">regenerate parts of their brains</a>, even if a large section was completely removed. But one study found that axolotl <a href="https://doi.org/10.7554/eLife.13998">brain regeneration</a> has a limited ability to rebuild original tissue structure.</p>
<p>So how perfectly can axolotl’s regenerate their brains after injury? </p>
<p>As a <a href="https://scholar.google.com/citations?user=OdA08uIAAAAJ&hl=en">researcher studying regeneration at the cellular level</a>, I and my colleagues in the <a href="https://bsse.ethz.ch/qdb">Treutlein Lab</a> at ETH Zurich and the <a href="http://tanakalab.org">Tanaka Lab</a> at the Institute of Molecular Pathology in Vienna wondered whether axolotls are able to regenerate all the different cell types in their brain, including the connections linking one brain region to another. In our <a href="https://science.org/doi/10.1126/science.abp9262">recently published study</a>, we created an atlas of the cells that make up a part of the axolotl brain, shedding light on both the way it regenerates and brain evolution across species.</p>
<h2>Why look at cells?</h2>
<p>Different <a href="https://doi.org/10.1038/nrg2416">cell types</a> have different functions. They are able to specialize in certain roles because they each express different genes. Understanding what types of cells are in the brain and what they do helps clarify the overall picture of how the brain works. It also allows researchers to make comparisons across evolution and try to find biological trends across species.</p>
<p>One way to understand which cells are expressing which genes is by using a technique called <a href="https://doi.org/10.3389/fgene.2019.00317">single-cell RNA sequencing (scRNA-seq)</a>. This tool allows researchers to count the number of active genes within each cell of a particular sample. This provides a “snapshot” of the activities each cell was doing when it was collected. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/k9VFNLLQP8c?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Single-cell RNA sequencing can provide information on the specific function of each cell in a sample.</span></figcaption>
</figure>
<p>This tool has been instrumental in understanding the types of cells that exist in the brains of animals. Scientists have used scRNA-seq in <a href="https://doi.org/10.1038%2Fnbt.4103">fish</a>, <a href="https://doi.org/10.1126/science.aar4237">reptiles</a>, <a href="https://doi.org/10.1016/j.cell.2018.06.021">mice</a> and even <a href="https://doi.org/10.1126/science.aap8809">humans</a>. But one major piece of the brain evolution puzzle has been missing: amphibians.</p>
<h2>Mapping the axolotl brain</h2>
<p>Our team decided to focus on the <a href="https://doi.org/10.1016/B978-0-323-39632-5.00016-5">telencephalon</a> of the axolotl. In humans, the telencephalon is the largest division of the brain and contains a region called the <a href="https://doi.org/10.1038/nrn2719">neocortex</a>, which plays a key role in animal behavior and cognition. Throughout recent evolution, the neocortex has <a href="https://doi.org/10.3389/fnana.2014.00015">massively grown in size</a> compared with other brain regions. Similarly, the types of cells that make up the telencephalon overall have <a href="https://doi.org/10.1016/j.pneurobio.2020.101865">highly diversified</a> and grown in complexity over time, making this region an intriguing area to study.</p>
<p>We used scRNA-seq to identify the different types of cells that make up the axolotl telencephalon, including different types of <a href="https://www.ninds.nih.gov/health-information/patient-caregiver-education/brain-basics-life-and-death-neuron">neurons</a> and <a href="https://doi.org/10.3389/fnana.2018.00104">progenitor cells</a>, or cells that can divide into more of themselves or turn into other cell types. We identified what genes are active when <a href="https://doi.org/10.3389/fcell.2020.00533">progenitor cells become neurons</a>, and found that many pass through an intermediate cell type called neuroblasts – previously unknown to exist in axolotls – before becoming mature neurons.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/uooR4293p_4?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Axolotls’ regenerative abilities have been a source of fascination for scientists.</span></figcaption>
</figure>
<p>We then put axolotl regeneration to the test by removing one section of their telencephalon. Using a <a href="https://doi.org/10.1126/science.aad7038">specialized method of scRNA-seq</a>, we were able to capture and sequence all the new cells at different stages of regeneration, from one to 12 weeks after injury. Ultimately, we found that all cell types that were removed had been completely restored.</p>
<p>We observed that brain regeneration happens in three main phases. The first phase starts with a rapid increase in the number of progenitor cells, and a small fraction of these cells activate a wound-healing process. In phase two, progenitor cells begin to differentiate into neuroblasts. Finally, in phase three, the neuroblasts differentiate into the same types of neurons that were originally lost.</p>
<p>Astonishingly, we also observed that the severed <a href="https://www.brainfacts.org/thinking-sensing-and-behaving/brain-development/2012/making-connections">neuronal connections</a> between the removed area and other areas of the brain had been reconnected. This rewiring indicates that the regenerated area had also regained its original function.</p>
<h2>Amphibians and human brains</h2>
<p>Adding amphibians to the evolutionary puzzle allows researchers to infer how the brain and its cell types has changed over time, as well as the mechanisms behind regeneration.</p>
<p>When we compared our axolotl data with other species, we found that cells in their telencephalon show strong similarity to the mammalian <a href="https://www.ncbi.nlm.nih.gov/books/NBK482171/">hippocampus</a>, the region of the brain involved in memory formation, and the <a href="https://doi.org/10.1016/B978-0-12-801238-3.04706-1">olfactory cortex</a>, the region of the brain involved in the sense of smell. We even found some similarities in one axolotl cell type to the neocortex, the area of the brain known for perception, thought and spatial reasoning in humans. These similarities indicate that these areas of the brain may be evolutionarily conserved, or stayed comparable over the course of evolution, and that the neocortex of mammals may have an ancestor cell type in the telencephalon of amphibians.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/482165/original/file-20220831-4904-pdq0jw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Axolotl in tank" src="https://images.theconversation.com/files/482165/original/file-20220831-4904-pdq0jw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/482165/original/file-20220831-4904-pdq0jw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/482165/original/file-20220831-4904-pdq0jw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/482165/original/file-20220831-4904-pdq0jw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/482165/original/file-20220831-4904-pdq0jw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/482165/original/file-20220831-4904-pdq0jw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/482165/original/file-20220831-4904-pdq0jw.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">Cracking the mystery of axolotl regeneration could lead to improvements in medical treatments for severe injuries.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Axolotl_ambystoma_mexicanum_anfibio_ASAG.jpg">Amandasofiarana/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>While our study sheds light on the process of brain regeneration, including which genes are involved and how cells ultimately become neurons, we still don’t know what <a href="https://www.nature.com/scitable/topicpage/cell-signaling-14047077/">external signals</a> initiate this process. Moreover, we don’t know if the processes we identified are still accessible to animals that evolved later in time, such as mice or humans.</p>
<p>But we’re not solving the brain evolution puzzle alone. The <a href="https://www.tosches-lab.com/">Tosches Lab</a> at Columbia University explored the diversity of cell types in <a href="https://science.org/doi/10.1126/science.abp9186">another species of salamander, <em>Pleurodeles waltl</em></a>, while the Fei lab at the Guangdong Academy of Medical Sciences in China and collaborators at life sciences company <a href="https://en.genomics.cn/">BGI</a> explored how cell types are <a href="https://science.org/doi/10.1126/science.abp9444">spatially arranged in the axolotl forebrain</a>.</p>
<p>Identifying all the cell types in the axolotl brain also helps pave the way for innovative research in regenerative medicine. The brains of mice and humans have <a href="https://doi.org/10.1100/tsw.2011.113">largely lost their capacity</a> to repair or regenerate themselves. <a href="https://doi.org/10.4103%2F1673-5374.270294">Medical interventions</a> for severe brain injury currently focus on drug and stem cell therapies to boost or promote repair. Examining the genes and cell types that allow axolotls to accomplish nearly perfect regeneration may be the key to improve treatments for severe injuries and unlock regeneration potential in humans.</p><img src="https://counter.theconversation.com/content/189519/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ashley Maynard works at ETH Zurich and has disclosed no relevant affiliations beyond her academic appointment.</span></em></p>Axolotls are amphibians known for their ability to regrow their organs, including their brains. New research clarifies their regeneration process.Ashley Maynard, PhD Candidate in Quantitative Developmental Biology, Swiss Federal Institute of Technology ZurichLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1865352022-07-24T12:28:50Z2022-07-24T12:28:50ZFinding their song: Reviving the declining western chorus frog population is now critical<figure><img src="https://images.theconversation.com/files/474439/original/file-20220717-12-38fv83.jpg?ixlib=rb-1.1.0&rect=19%2C96%2C4262%2C2747&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The population of western chorus frogs has been declining over the past 60 years and continues to be an issue across Canada.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>In November 2021, Canadian Minister of Environment and Climate Change Steven Guilbeault declared <a href="https://www.canada.ca/en/environment-climate-change/services/species-risk-public-registry/orders/western-chorus-frog-longueuil-emergency-protection-order-summary.html">an emergency order that put an immediate halt</a> on a residential development in Longueuil, Que., to protect the critical habitat of one of Canada’s threatened amphibian species — the western chorus frog. </p>
<p>While this was one of the few cases where the federal government applied the Species at Risk Act to cease development on private land, the Canadian Shield’s population of western chorus frog — in addition to many other <a href="https://doi.org/10.1186/s12983-021-00425-w">closely related species</a> — has declined over the past 60 years and <a href="https://longpointbiosphere.com/download/Herptiles/Perspectives-on-amphibiam-population-declines-Green-1997.pdf">continues to be an issue in Canada</a>. </p>
<p>It was recently announced that the proposed route of Highway 413 in Ontario will impact the habitat of <a href="https://thenarwhal.ca/highway-413-endangered-species/?fbclid=IwAR0sh374OVqgaqor0eLVB8fX-VQT3omUYnUp8FccKe8CcMgQiJ4_QFkMhPI">11 species at risk</a>, including the western chorus frog. The recent disappearance of this frog and its habitat — specially in portions of Ontario and Québec — has caused substantial <a href="https://www.cbc.ca/news/canada/montreal/game-changer-court-ruling-gives-federal-government-right-to-protect-western-chorus-frog-1.4741646">concern and controversy</a>.</p>
<p>As a behavioural ecologist specializing in acoustics and a reproductive endocrinologist who invented an <a href="https://doi.org/10.1016/j.ygcen.2016.03.024">injectable hormone mixture</a> that induces frog breeding, we believe hope still exists. Habitat protection and restoration, advanced reproductive technologies and reintroduction procedures are all at our fingertips. This multifaceted approach could help slow further declines of chorus frogs and other amphibians. </p>
<h2>Global and local threats</h2>
<p>Despite its small size — measuring only two to three centimetres in length and often weighing less than two grams — the western chorus frog produces a loud, clear trill that is reminiscent of running a thumb across a plastic comb. </p>
<p>Historically, it was one of the most abundant amphibians in eastern Ontario and Québec. Now, it is found in <a href="https://www.canada.ca/en/environment-climate-change/services/species-risk-public-registry/recovery-strategies/western-chorus-frog-canadian-shield-population.html">only 10 per cent of their original range</a>.</p>
<figure class="align-right ">
<img alt="A dark brown frog with light brown markings" src="https://images.theconversation.com/files/473222/original/file-20220708-27-8qc00h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/473222/original/file-20220708-27-8qc00h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=486&fit=crop&dpr=1 600w, https://images.theconversation.com/files/473222/original/file-20220708-27-8qc00h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=486&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/473222/original/file-20220708-27-8qc00h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=486&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/473222/original/file-20220708-27-8qc00h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=611&fit=crop&dpr=1 754w, https://images.theconversation.com/files/473222/original/file-20220708-27-8qc00h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=611&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/473222/original/file-20220708-27-8qc00h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=611&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An adult female western chorus frog (Pseudacris triseriata).</span>
<span class="attribution"><span class="source">(Chris Callaghan)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Amphibians, including the western chorus frog and other frogs, toads and salamanders, play critical ecological roles in the environment. They are vital pieces in the local food chain. They are also economically important, as they provide free pest control in residential areas by consuming insect species, such as mosquitoes and blackflies, without the need of <a href="https://theconversation.com/are-mosquito-killing-natural-pesticides-unintentionally-harming-frogs-175194">pesticides that are potentially harmful to wildlife</a>. </p>
<p>Across the world, these amphibian species are rapidly disappearing due to habitat loss, disease, pollution, harvesting, invasive species and <a href="https://doi.org/10.1038/35070552">climate change</a>. Over 40 per cent of species are <a href="https://journals.openedition.org/sapiens/1406">threatened with extinction</a>. Amphibian declines are part of the <a href="https://doi.org/10.1073/pnas.0801921105">sixth mass extinction</a> event on Earth, on a scale that is approaching the loss of dinosaurs. </p>
<h2>Captive breeding can aid reintroduction of frogs</h2>
<p>One strategy for conserving declining species is to collect individuals from the wild and breed them in <a href="https://doi.org/10.1111/cobi.12612">laboratory or captive settings</a>.</p>
<p>This allows the offspring to grow without being threatened by predators, contaminants or other disturbances. The healthy offspring can then be released to boost numbers in the natural environment. </p>
<p>Along with Marc Mazerolle’s team at Laval University, we implemented this strategy through a recent collaborative effort with the Montreal Biodome and Sépaq (Société des établissements de plein air du Québec), with the goal of increasing the number of healthy individuals that can be released into appropriate restored natural sites to the benefit of all.</p>
<p>Two years into the project, adult chorus frogs have been successfully bred in captivity. Hundreds of tadpoles have been reared to froglets and released in constructed wetlands for the species. Some of the introduced individuals survived their first winter and adult males could be heard calling for females this past spring. These methods can be applied to species around the world.</p>
<h2>The critical role of awareness and conservation</h2>
<p>The first step is to spread awareness to emphasize the importance of amphibians and the speed at which species are declining. There are several resources and citizen science projects dedicate to the protection of amphibians, such as <a href="http://amphibian-reptile-conservation.org/index.html">Partners in Amphibian and Reptile Conservation</a> and <a href="https://www.amphibians.org/">Amphibian Survival Alliance</a>.</p>
<p>Protection of wetlands from destruction and pollution is one of the best ways to help. Wetlands are critical to the survival of amphibians. During the construction of housing developments and infrastructure — such as the proposed Highway 413 — wetlands are often <a href="https://trid.trb.org/view/148062">drained or filled in</a>. Wetlands host many beautiful bird and plant species, not only amphibians, and they act as the earth’s filter to <a href="https://doi.org/10.1016/j.tree.2005.11.015">increase water quality</a>.</p>
<figure class="align-center ">
<img alt="A wetland" src="https://images.theconversation.com/files/473266/original/file-20220710-7520-dxircz.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/473266/original/file-20220710-7520-dxircz.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/473266/original/file-20220710-7520-dxircz.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/473266/original/file-20220710-7520-dxircz.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/473266/original/file-20220710-7520-dxircz.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/473266/original/file-20220710-7520-dxircz.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/473266/original/file-20220710-7520-dxircz.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">
<figcaption>
<span class="caption">Wetlands act as typical habitats for western chorus frogs and other amphibians.</span>
<span class="attribution"><span class="source">(Jeffrey P. Ethier)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Being careful while walking or driving near wetlands is another way to help on an individual level. Avoid disturbing breeding amphibians. Leave the tadpoles in the water. Observe and enjoy watching them grow legs and climb out of the water for the first time! Protecting the local ponds near your home can also contribute to this conservation.</p>
<p>You can also participate in public forums and let your community know that you support sustainable and responsible land use that keeps wetland habitats connected and protects critical areas for threatened species. Form volunteer groups to help protect frogs as they migrate over roads in the spring breeding season, <a href="https://www.researchgate.net/publication/233740122_40_years_of_Natterjack_toad_Conservation_in_Europe">as seen in other countries</a>. We all have the power to make a positive difference in the protection of amphibians.</p><img src="https://counter.theconversation.com/content/186535/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jeffrey Ethier receives funding from the Natural Sciences and Engineering Research Council of Canada (NSERC). </span></em></p><p class="fine-print"><em><span>Vance L Trudeau receives funding from Environment and Climate Change Canada and Ministère des Forêts, de la Faune et des Parcs.</span></em></p>Habitat protection and restoration, advanced reproductive technologies and reintroduction procedures could help slow the decline of western chorus frogs and other amphibians.Jeffrey P. Ethier, PhD candidate, Department of Biology, L’Université d’Ottawa/University of OttawaVance L Trudeau, Professor, Department of Biology, L’Université d’Ottawa/University of OttawaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1869642022-07-18T09:06:58Z2022-07-18T09:06:58ZFive ways to help wildlife in heatwaves<p>Extremely hot weather is becoming more common. The top ten warmest years since 1884 all happened <a href="https://rmets.onlinelibrary.wiley.com/doi/10.1002/joc.7285">in the last two decades</a>. While experts can help people take adequate precautions to beat the heat, who’s looking out for the rest of the animal kingdom?</p>
<p>Hot temperatures are uncomfortable and potentially deadly for wildlife too. Fortunately, you can give a helping hand with a few easy steps.</p>
<h2>1. Provide water</h2>
<p>Hot weather can be great for some wildlife. Butterfly populations in the UK tend to bounce back from <a href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2656.2001.00480.x">hot and dry summers</a>, possibly because this increases the survival of their larvae. </p>
<p>But even heat-loving species can only thrive if they can also find <a href="https://theconversation.com/wildlife-winners-and-losers-in-britains-summer-heatwave-100408">enough to drink</a>. Even if you don’t have a garden, putting out a shallow dish of water will benefit a wide variety of wildlife. Add marbles or stones to it so that butterflies and bees can climb out if they fall in. </p>
<figure class="align-center ">
<img alt="A honeybee sips from the edge of a blue water dish filled with pebbles." src="https://images.theconversation.com/files/474283/original/file-20220715-20-330cip.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/474283/original/file-20220715-20-330cip.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=272&fit=crop&dpr=1 600w, https://images.theconversation.com/files/474283/original/file-20220715-20-330cip.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=272&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/474283/original/file-20220715-20-330cip.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=272&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/474283/original/file-20220715-20-330cip.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=342&fit=crop&dpr=1 754w, https://images.theconversation.com/files/474283/original/file-20220715-20-330cip.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=342&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/474283/original/file-20220715-20-330cip.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=342&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Parched: insects need to stay hydrated too.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/honeybee-drinking-water-bowl-light-expanded-2019263285">BernadetteB/Shutterstock</a></span>
</figcaption>
</figure>
<p>A shallow dish on the ground might attract hedgehogs or foxes, and one placed higher up could serve as a makeshift birdbath. If you’re feeling more ambitious, you could create a miniature pond. It’s possible to make a simple one from <a href="https://www.wildlifetrusts.org/actions/how-create-mini-pond">an old washing-up bowl</a>. </p>
<p>You don’t even need to dig a hole if you include a ramp from the ground. Add gravel and rocks, plus logs or larger stones, then fill with rainwater (<a href="https://www.screwfix.com/c/outdoor-gardening/water-butts/cat1660006">a water butt</a> is useful for collecting and storing it). Include a few <a href="https://www.squiresgardencentres.co.uk/news/best-pond-plants/">pond plants</a>, such as <a href="https://www.wildlifetrusts.org/wildlife-explorer/wildflowers/spiked-water-milfoil">spiked water milfoil</a>, to oxygenate the water. You can find these at your local garden centre.</p>
<p>Rare <a href="https://www.sciencedirect.com/science/article/pii/S0003347200916270">natterjack toads</a> cannot detect new sources of water, so they can only find ponds they have visited before. But many other animals are able to <a href="https://www.sciencedirect.com/science/article/pii/S0003347285701273">sense sources of water</a> from far away. That’s why it’s important to drain or cover paddling pools overnight to prevent any animals <a href="https://www.hedgehogstreet.org/garden-hazards/">climbing in and drowning</a>.</p>
<h2>2. Provide shelter</h2>
<p>It’s much cooler out of the sun. You can help animals by offering them somewhere cool to rest. A pile of logs in a shady corner will have places for insects to hide (and present a tasty snack bar for larger wildlife). Heatwaves are not the time to trim your garden either – leave any plants uncut. They’ll provide shelter, and food if they’ve gone to seed.</p>
<figure class="align-center ">
<img alt="A pile of logs in a garden." src="https://images.theconversation.com/files/474284/original/file-20220715-22-karcgh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/474284/original/file-20220715-22-karcgh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=405&fit=crop&dpr=1 600w, https://images.theconversation.com/files/474284/original/file-20220715-22-karcgh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=405&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/474284/original/file-20220715-22-karcgh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=405&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/474284/original/file-20220715-22-karcgh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=509&fit=crop&dpr=1 754w, https://images.theconversation.com/files/474284/original/file-20220715-22-karcgh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=509&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/474284/original/file-20220715-22-karcgh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=509&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A cool retreat.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/pile-wood-logs-garden-431335075">Allik/Shutterstock</a></span>
</figcaption>
</figure>
<h2>3. Provide food</h2>
<p>Leaves, fruits, seeds and roots are all food for different animals to eat. But the hot weather will be making plants wilt. Make sure flowers and berry-producing plants survive the heatwave by keeping them well-watered. If you normally feed the birds, make sure your feeders are well stocked.</p>
<h2>4. Create habitats</h2>
<p>As well as helping animals in immediate heatwaves, you can also do things for the long term. Many UK species are on the move as the climate warms, shifting the areas they are <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.12823">usually found in</a>. For example, between 1981 and 2000, European curlews (Europe’s largest and perhaps most distinctive wading bird with its curved, slender beak) moved <a href="https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2008.01666.x">119 km north-east</a>. </p>
<p>By analysing the movements of UK invertebrates over 40 years, scientists discovered that the species which eventually found new <a href="https://www.nature.com/articles/s41598-019-51582-2">suitable habitats</a> moved further than those which were restricted by fewer rarer habitats they depended on. You can help make more of these migrations a success by making your local area more accommodating for a wide range of species.</p>
<p>For example, plant bee-friendly flowers such as <a href="https://peerj.com/articles/3066/">sage or lavender</a> in window boxes and on balconies. If you have a lawn, why not turn it into a wildflower meadow? These habitats are more tolerant of drought the <a href="https://www.sciencedirect.com/science/article/pii/S0169204610001519?via%3Dihub">more species they contain</a>. They mean better for wildlife and less mowing for you. </p>
<p>If you have the space, adding a pond will give refuge to amphibians <a href="https://www.conservationevidence.com/actions/869">like frogs and newts</a>. Just make sure that at <a href="https://www.wildlifetrusts.org/actions/how-build-pond">least one side is shallower</a> to allow larger animals like squirrels or hedgehogs to climb out if they fall in.</p>
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Read more:
<a href="https://theconversation.com/how-to-make-your-lawn-wildlife-friendly-all-year-round-tips-from-an-ecologist-183692">How to make your lawn wildlife friendly all year round – tips from an ecologist</a>
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<h2>5. Reduce the heat</h2>
<p>Compared to plants, surfaces like artificial lawns and concrete slabs absorb more heat in the day and release that heat to the air at night. When in the sun, concrete paving can be <a href="https://www.sciencedirect.com/science/article/pii/S1618866712000611">more than 20°C hotter</a> than grass – too hot for us or wildlife to stand on. So why not replace hard and artificial surfaces with plants?</p>
<p>Shading from trees can reduce surface temperatures <a href="https://www.nature.com/articles/s41467-021-26768-w">by around 10°C</a>, so planting a native tree in your garden would cool you and wildlife. The elder (<em>Sambucus nigra</em>) in my garden provides berries and flowers which are great for wildlife, and grows a couple of metres each year. </p>
<p>Elders can also be pruned to suit the size of your garden too – either as a bush or a tree. If you plant one soon it could be offering shade to your garden and shelter for nesting birds by next summer.</p>
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<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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<hr><img src="https://counter.theconversation.com/content/186964/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sarah Papworth has received funding from the National Geographic Society, the Natural Environment Research Council, the Zoological Society of London and the Royal Society for the Protection of Birds. She is a member of the Green Party. </span></em></p>If you’re hot, so are your four-legged neighbours.Sarah Papworth, Senior Lecturer in Conservation Biology, Royal Holloway University of LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1855832022-06-23T20:08:24Z2022-06-23T20:08:24ZWe helped track 77 species for up to 60 years to try to reveal the secrets of long life. And some don’t seem to age at all<figure><img src="https://images.theconversation.com/files/470484/original/file-20220623-7584-nu1tiw.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Mike Gardner</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Ever wondered about the secret to a long life? Perhaps understanding the lifespans of other animals with backbones (or “vertebrates”) might help us unlock this mystery.</p>
<p>You’ve probably heard turtles live a long (and slow) life. At 190 years, <a href="https://www.smithsonianmag.com/smart-news/at-190-jonathan-the-tortoise-is-the-worlds-oldest-living-land-animal-180979514/">Jonathan</a> the Seychelles giant tortoise might be the oldest land animal alive. But why do some animals live longer than others?</p>
<p>Research <a href="https://www.science.org/doi/10.1126/science.abm0151">published today</a> by myself and colleagues in the journal Science investigates the various factors that may affect longevity (lifespan) and ageing in reptiles and amphibians.</p>
<p>We used long-term data from 77 different species of reptiles and amphibians – all cold-blooded animals. Our work is a collaboration between more than 100 scientists with up to 60 years of data on animals that were caught, marked, released and re-caught.</p>
<p>These data were then compared to existing information on warm-blooded animals, and several different ideas about ageing emerged.</p>
<h2>What factors might be important?</h2>
<h1>Cold-blooded or warm-blooded</h1>
<p>One popular line of thought we investigated is the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4843886/">idea</a> that cold-blooded animals such as frogs, salamanders and reptiles live longer because they age more <em>slowly</em>.</p>
<p>These animals have to rely on external temperatures to help regulate their body temperature. As a result they have slower “metabolisms” (the rate at which they convert what they eat and drink into energy).</p>
<p>Animals that are small and warm-blooded, such as mice, age quickly since they have faster metabolisms – and turtles age slowly since they have slower metabolisms. By this logic, cold-blooded animals should have lower metabolisms than similar-sized warm-blooded ones. </p>
<p>However, we found cold-blooded animals don’t age more slowly than similar-sized warm-blooded ones. In fact, the variation in ageing in the reptiles and amphibians we looked at was much greater than previously predicted. So the reasons vertebrates age are more complex than this idea sets out. </p>
<h1>Environmental temperature</h1>
<p>Another related <a href="https://academic.oup.com/biolinnean/article/125/4/730/5145102?login=true">theory</a> is that environmental temperature itself could be a driver for longevity. For instance, animals in colder areas might be processing food more slowly and have periods of inactivity, such as with hibernation – leading to an overall increase in lifespan. </p>
<p>Under this scenario, both cold and warm-blooded animals in colder areas would live longer than animals in warmer areas. </p>
<p>We found this was true for reptiles as a group, but not for amphibians. Importantly, this finding has implications for the effects of global warming, which might lead to reptiles ageing faster in permanently warmer environments.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/470478/original/file-20220623-51865-930myg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="The stripy brown small lizard sits on a rock" src="https://images.theconversation.com/files/470478/original/file-20220623-51865-930myg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/470478/original/file-20220623-51865-930myg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/470478/original/file-20220623-51865-930myg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/470478/original/file-20220623-51865-930myg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/470478/original/file-20220623-51865-930myg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/470478/original/file-20220623-51865-930myg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/470478/original/file-20220623-51865-930myg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&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 Viviparous lizard (<em>Zootoca vivipara</em>) is one of the cold-blooded species we studied.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/viviparous-lizard-zootoca-vivipara-34699252">Shutterstock</a></span>
</figcaption>
</figure>
<h1>Protection</h1>
<p>One <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/jeb.12143">suggestion</a> is that animals with certain types of protections, such as protruding spines, armour, venom or shells, also don’t age as fast and therefore live longer. </p>
<p>A lot of energy is put into producing these protections, which can allow animals to live longer by making them less vulnerable to predation. However, could it be the very fact of having these protections allows animals to age more slowly?</p>
<p>Our work found this to be true. It seems having such protections does lead to animals living longer. This is especially true for turtles, which have hard shell protection and incredibly long lifespans.</p>
<p>We’ll need to conduct more research to figure out why just having protections is linked to a longer life.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/470483/original/file-20220623-51187-mpi2xr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A crocodile sits on the bank of a river with its mouth open" src="https://images.theconversation.com/files/470483/original/file-20220623-51187-mpi2xr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/470483/original/file-20220623-51187-mpi2xr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/470483/original/file-20220623-51187-mpi2xr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/470483/original/file-20220623-51187-mpi2xr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/470483/original/file-20220623-51187-mpi2xr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/470483/original/file-20220623-51187-mpi2xr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/470483/original/file-20220623-51187-mpi2xr.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">One species of crocodile studied, <em>Crocodylus johnsoni</em>, has a powerful armoured body with protruding scales that protect it from predation.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/freshwater-crocodile-crocodylus-johnstoni-species-endemic-1541741615">Shutterstock</a></span>
</figcaption>
</figure>
<h1>Reproduction</h1>
<p>Finally, it has been <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0066670">posited</a> that perhaps longevity is linked to how late into life an animal reproduces. </p>
<p>If they can keep reproducing later into life, then natural selection would drive this ability, generation to generation, allowing these animals to live longer than those that reproduce early and can’t continue to do so.</p>
<p>Indeed, we found animals that start producing offspring at a later age do seem to live longer lives. Sleepy lizards (or shinglebacks) are a great example. They don’t reproduce until they’re about five years old, and live until they’re close to 50!</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/breakthrough-allows-scientists-to-determine-the-age-of-endangered-native-fish-using-dna-162084">Breakthrough allows scientists to determine the age of endangered native fish using DNA</a>
</strong>
</em>
</p>
<hr>
<h2>The challenge in understanding ageing</h2>
<p>To understand ageing, we need a lot of data on the same animals. That’s simply because if we want to know how long a species lives, we have to keep catching the same individuals over and over, across large spans of time. </p>
<p>This is “longitudinal” research. Luckily, it’s exactly what some scientists have committed themselves to. It’s also what my team is doing with sleepy lizards, <em>Tiliqua rugosa</em>. These lizards have been studied continuously at Bundey Bore station in the Mid North of South Australia since 1982. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/470225/original/file-20220622-3398-sv0ijc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/470225/original/file-20220622-3398-sv0ijc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/470225/original/file-20220622-3398-sv0ijc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/470225/original/file-20220622-3398-sv0ijc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/470225/original/file-20220622-3398-sv0ijc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/470225/original/file-20220622-3398-sv0ijc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/470225/original/file-20220622-3398-sv0ijc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/470225/original/file-20220622-3398-sv0ijc.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"></a>
<figcaption>
<span class="caption">The sleepy lizard is one of the species used in the longevity study. As far as we know, this species lives up to 50 years.</span>
<span class="attribution"><span class="source">Mike Gardner</span></span>
</figcaption>
</figure>
<p>Here, more than 13,000 lizards have been caught over 40 years of study. Some have been caught up to 60 times! But given the 45-year longevity of these lizards, we’ve been studying them for a shorter time than some of them live. By keeping the survey work going we might find they live even longer. </p>
<h2>Some animals’ chance of dying isn’t linked to age</h2>
<p>Another interesting part of this research was finding, for a range of animals, that their chance of dying is just as small when they’re quite old compared to when they’re young. This “negligible ageing” is found in at least one species across each of frogs, salamanders, lizards, crocodiles and, of course, in tortoises like Jonathon. </p>
<p>We’re not quite sure why this is. The next challenge is to find out – perhaps by analysing species genomes. Knowing some animals have negligible ageing means we can target these species for future investigations. </p>
<p>Understanding what drives long life in other animals might lead to different biomedical targets to study humans too. We might not live to Jonathan the tortoise’s age, but we could theoretically use this knowledge to develop therapies that help stop some of the ageing process in us. </p>
<p>For now, healthy eating and exercising remain surer ways to a longer life.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-search-to-extend-lifespan-is-gaining-ground-but-can-we-truly-reverse-the-biology-of-ageing-75127">The search to extend lifespan is gaining ground, but can we truly reverse the biology of ageing?</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/185583/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mike Gardner receives funding from the Australian Research Council. He is affiliated with The South Australian Museum. </span></em></p>Our research is countering some previous ideas about what factors might slow down ageing. Further study could help us create targeted treatments in humans too.Mike Gardner, Flinders UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1842552022-06-12T23:03:08Z2022-06-12T23:03:08ZAustralian frogs are dying en masse again, and we need your help to find out why<figure><img src="https://images.theconversation.com/files/467946/original/file-20220609-17-ai0xws.jpg?ixlib=rb-1.1.0&rect=8%2C5%2C1908%2C1270&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A dead Peron's tree frog (_Litoria peronii_)</span> <span class="attribution"><span class="source">Ken Griffiths</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Last winter, thousands of dead and dying frogs were found across Australia. Instead of hunkering down and out of sight, frogs were spotted during the day in the open, on footpaths, highways and doorsteps – often in the blazing sun.</p>
<p>These frogs were often thin, slow moving, and with dark patches on their back or red bellies. They were seeking water in pet bowls or pot plants. And they usually died in a matter of hours.</p>
<p>A crash in frog populations could have very real consequences, particularly for already threatened frog species, and the importance of frogs in both freshwater and land systems means it can also impact entire ecosystems. </p>
<p>Thankfully, reports of sick or dead frogs slowed as the weather got warmer, and by the end of last year they had all but ceased. We hoped the awful spate of frog deaths was a one-off. But now, we fear it is happening again. </p>
<p>In the last few weeks, we’ve started getting scarily similar reports of sick and dead frogs from people across Australia. </p>
<p>From Warwick in southeast Queensland, we’ve received emails reporting green tree frogs (<em>Litoria caerulea</em>), discoloured and hunched up, sitting in the open, with the upsetting email: </p>
<blockquote>
<p>We normally have these beautiful creatures hopping around our house but in the last week have only spotted two. Both were dead.</p>
</blockquote>
<p>From Sydney’s North Shore, another report:</p>
<blockquote>
<p>I have just found a dead Peron’s tree frog when raking up leaves in my garden.</p>
</blockquote>
<p>And most recently, one of our colleagues stumbled across a big green tree frog in the middle of the day while bird-watching in western Sydney. The bright green frog was sitting in the sun on an asphalt path. In only a few hours, the frog was dead. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/467949/original/file-20220609-24-a36wuv.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/467949/original/file-20220609-24-a36wuv.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/467949/original/file-20220609-24-a36wuv.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/467949/original/file-20220609-24-a36wuv.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/467949/original/file-20220609-24-a36wuv.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/467949/original/file-20220609-24-a36wuv.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/467949/original/file-20220609-24-a36wuv.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/467949/original/file-20220609-24-a36wuv.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"></a>
<figcaption>
<span class="caption">A big green tree frog sitting on a hot asphalt path. It died in a matter of hours.</span>
<span class="attribution"><span class="source">Nadiah Roslan</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>How many frogs died last year?</h2>
<p>Photos of sick frogs started popping up on social media feeds in May last year. This was not initially alarming, as sick, old or injured frogs are most likely to die in winter as their <a href="https://besjournals.onlinelibrary.wiley.com/doi/10.1111/j.1365-2435.2006.01159.x">immune system slows down</a>. </p>
<p>However, reports increased over late June and July, and we began to worry about just how many frogs were dying. Unfortunately, just as we began to worry, we were in lockdown, unable to venture out and investigate for ourselves. </p>
<p>So we <a href="https://theconversation.com/dead-shrivelled-frogs-are-unexpectedly-turning-up-across-eastern-australia-we-need-your-help-to-find-out-why-165176">asked the community for help</a>. We asked for reports of sick or dead frogs, and then aligned members of the public with local veterinary clinics willing to take in these frogs for examination, care and diagnostic sample collection. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/467952/original/file-20220609-12-bb4522.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/467952/original/file-20220609-12-bb4522.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/467952/original/file-20220609-12-bb4522.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/467952/original/file-20220609-12-bb4522.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/467952/original/file-20220609-12-bb4522.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/467952/original/file-20220609-12-bb4522.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/467952/original/file-20220609-12-bb4522.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/467952/original/file-20220609-12-bb4522.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"></a>
<figcaption>
<span class="caption">A dead, shrivelled green tree frog found by a member of the public.</span>
<span class="attribution"><span class="source">Suzanne Mcgovern</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/467956/original/file-20220609-16-dr91o2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/467956/original/file-20220609-16-dr91o2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/467956/original/file-20220609-16-dr91o2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=699&fit=crop&dpr=1 600w, https://images.theconversation.com/files/467956/original/file-20220609-16-dr91o2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=699&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/467956/original/file-20220609-16-dr91o2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=699&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/467956/original/file-20220609-16-dr91o2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=879&fit=crop&dpr=1 754w, https://images.theconversation.com/files/467956/original/file-20220609-16-dr91o2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=879&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/467956/original/file-20220609-16-dr91o2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=879&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Another dead, discoloured green tree frog.</span>
<span class="attribution"><span class="source">Jayne Barrett</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>This meant the welfare of frogs could be assured, and we could begin our scientific investigation into the cause once lockdown ended. </p>
<p>Reports came flooding in. Across Australia, a remarkable 1,600 people reported finding sick or dead frogs. Each report often described dozens of dead frogs, making the grim tally in the thousands. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/dead-shrivelled-frogs-are-unexpectedly-turning-up-across-eastern-australia-we-need-your-help-to-find-out-why-165176">Dead, shrivelled frogs are unexpectedly turning up across eastern Australia. We need your help to find out why</a>
</strong>
</em>
</p>
<hr>
<p>Although most sick and dead frogs reported were green tree frogs, this is likely because this species tends to hang around houses and be spotted more. Frog species <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.15623">less tolerant of suburbia</a> are far less likely to be seen. </p>
<p>Despite this, more than 40 species were reported, including threatened species such as the green and golden bell frog (<em>Litoria aurea</em>) and the giant barred frog (<em>Mixophyes iteratus</em>).</p>
<p>The true death count and full list of species impacted is likely to be orders of magnitude higher.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/467958/original/file-20220609-16-aepust.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/467958/original/file-20220609-16-aepust.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/467958/original/file-20220609-16-aepust.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/467958/original/file-20220609-16-aepust.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/467958/original/file-20220609-16-aepust.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/467958/original/file-20220609-16-aepust.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/467958/original/file-20220609-16-aepust.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/467958/original/file-20220609-16-aepust.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 green and golden bell frog, <em>Litoria aurea</em></span>
<span class="attribution"><span class="source">Jodi Rowley</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/467960/original/file-20220609-22-mz9zxs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/467960/original/file-20220609-22-mz9zxs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/467960/original/file-20220609-22-mz9zxs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/467960/original/file-20220609-22-mz9zxs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/467960/original/file-20220609-22-mz9zxs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/467960/original/file-20220609-22-mz9zxs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/467960/original/file-20220609-22-mz9zxs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/467960/original/file-20220609-22-mz9zxs.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 giant barred frog, <em>Mixophyes iteratus</em></span>
<span class="attribution"><span class="source">Jodi Rowley</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Why are the frogs dying?</h2>
<p>We’ve been working with universities, government biosecurity and environment agencies to understand just what caused frogs to die last winter. </p>
<p>Our investigation has only been made possible due to the efforts of people across Australia reporting sick and dead frogs, taking sick frogs to veterinary clinics and freezing dead frogs for us to pick up and test ourselves. </p>
<p>In New South Wales alone, more than 350 people froze dead frogs for us to collect. Without this help, we would still be at square one with our investigation. </p>
<p>It’s a murder mystery, and there are so many possible suspects. We’ve been testing for parasitic, bacterial, viral and fungal pathogens. These tests include looking for pathogens known to kill frogs, and also looking for possible novel pathogens, which is by far the harder task. The potential role of toxins is also being assessed.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/467961/original/file-20220609-14-jomj7s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/467961/original/file-20220609-14-jomj7s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/467961/original/file-20220609-14-jomj7s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1067&fit=crop&dpr=1 600w, https://images.theconversation.com/files/467961/original/file-20220609-14-jomj7s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1067&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/467961/original/file-20220609-14-jomj7s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1067&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/467961/original/file-20220609-14-jomj7s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1340&fit=crop&dpr=1 754w, https://images.theconversation.com/files/467961/original/file-20220609-14-jomj7s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1340&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/467961/original/file-20220609-14-jomj7s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1340&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 dead green stream frog, <em>Litoria phyllochroa</em></span>
<span class="attribution"><span class="source">Andrew Jennings</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Right from the very first frog deaths last year, our number one suspect has been the amphibian chytrid fungus (<em>Batrachochytrium dendrobatidis</em>). This pathogen is a known frog killer, responsible for causing frog population declines and species extinctions around the world, including in Australia. </p>
<p>The fungus attacks the skin of frogs, which is their Achilles heel – frogs use their skin to breathe, drink and control electrolytes. Deaths of frogs due to this pathogen are <a href="https://onlinelibrary.wiley.com/doi/10.1111/j.1751-0813.2004.tb11137.x">often at cooler temperatures</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-deadly-fungus-threatens-to-wipe-out-100-frog-species-heres-how-it-can-be-stopped-117842">A deadly fungus threatens to wipe out 100 frog species – here's how it can be stopped</a>
</strong>
</em>
</p>
<hr>
<p>Our testing has revealed the amphibian chytrid fungus is certainly involved in this mass death event. Most of the hundreds of dead frogs tested so far have tested positive for the pathogen. </p>
<p>But we aren’t yet sure if the fungus is acting alone, or even the primary cause of death. We continue to test for an array of other pathogens, toxins and other potential stressors. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/467962/original/file-20220609-14-fwy2pa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/467962/original/file-20220609-14-fwy2pa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/467962/original/file-20220609-14-fwy2pa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/467962/original/file-20220609-14-fwy2pa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/467962/original/file-20220609-14-fwy2pa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/467962/original/file-20220609-14-fwy2pa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/467962/original/file-20220609-14-fwy2pa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/467962/original/file-20220609-14-fwy2pa.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">A healthy green tree frog.</span>
<span class="attribution"><span class="source">Jodi Rowley</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Why should we care?</h2>
<p>Australia has <a href="https://www.frogid.net.au/frogs">247 known species of native frog</a>, <a href="https://www.environment.gov.au/cgi-bin/sprat/public/publicthreatenedlist.pl">40 of which are threatened with extinction</a>, and at least four species are already extinct. </p>
<p>The impacts on Australia’s frog species from such large scale deaths are unknown, but scientific surveys of frogs, combined with large scale <a href="https://www.frogid.net.au/">citizen science data</a> are underway.</p>
<p>Frogs are often extremely <a href="https://www.publish.csiro.au/zo/zo97062">abundant</a>, and play an important role in the flow of energy and nutrients, and in food webs. In places where amphibians have declined, the impacts are noticeable, with ripple effects <a href="https://www.jstor.org/stable/23501304">across entire ecosystems</a> as animals that rely on frogs for food start to disappear, too.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/UDwU9JR1vM8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The 26 Australian frog species at greatest risk of extinction.</span></figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/clicks-bonks-and-dripping-taps-listen-to-the-calls-of-6-frogs-out-and-about-this-summer-150084">Clicks, bonks and dripping taps: listen to the calls of 6 frogs out and about this summer</a>
</strong>
</em>
</p>
<hr>
<h2>We need your help</h2>
<p>To help us understand the scale and cause of any frog deaths this winter, please send any reports of sick or dead frogs to the Australian Museum’s citizen science project <a href="https://www.frogid.net.au/">FrogID</a> via calls@frogid.net.au. </p>
<p>Please include your location and, if possible, photos of the frog(s).</p>
<p>To help us determine the impact of frog deaths on Australia’s frogs, and which species are likely to need our help the most, please download the free <a href="https://www.frogid.net.au/">FrogID</a> app and record calling frogs whenever you can. </p>
<p>Every recording will help us better understand and conserve Australia’s frogs.</p><img src="https://counter.theconversation.com/content/184255/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jodi Rowley is the Lead Scientist of the Australian Museum's citizen science project, FrogID. She has received funding from the Department of Agriculture, Water and the Environment, Perth Zoo, the Australian Museum Foundation and other state, federal and philanthropic agencies.</span></em></p><p class="fine-print"><em><span> Karrie Rose leads the Australian Registry of Wildlife Health, a collaboration between Taronga Conservation Society Australia and the University of Sydney. The Registry is funded by Taronga Conservation Society Australia, service agreements and project-based funding from state, commonwealth and philanthropic agencies.</span></em></p>Thousands of sick and dead frogs are turning up around Australia, bizarrely lying out in the open. If you see one, let these scientists know.Jodi Rowley, Curator, Amphibian & Reptile Conservation Biology, Australian Museum, UNSW SydneyKarrie Rose, Australian Registry of Wildlife Health - Taronga Conservation Society Australia, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1662572021-08-23T16:17:17Z2021-08-23T16:17:17ZLizards, snakes and turtles: Dispelling the myths about reptiles as pets<figure><img src="https://images.theconversation.com/files/417105/original/file-20210819-15-1pi9z04.jpg?ixlib=rb-1.1.0&rect=40%2C16%2C5422%2C3620&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Leopard geckos make fun and entertaining pets.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Reptiles are all the rage. Mochi the bearded dragon is a viral sensation, <a href="https://ca.news.yahoo.com/bearded-dragon-comes-running-towards-211839614.html">with over 1.8 million views on YouTube</a>. Meanwhile, Chris Pratt is <a href="https://www.reptilesmagazine.com/actor-chris-pratt-takes-his-bearded-dragon-out-for-a-walk/">singing to his bearded dragon while walking it on a leash</a>, and he is just one of <a href="https://www.reptiles.swelluk.com/blog/10-celebrity-reptile-owners/">many other celebrities</a> with pet reptiles. It is obvious that having reptiles as pets has gained popularity in recent years. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/D4-VgAeUssI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Mochi the bearded dragon responds to his name being called.</span></figcaption>
</figure>
<p>But there is a growing number of people opposed to <a href="https://www.floridatoday.com/story/news/2021/02/25/emotions-proposed-florida-reptile-ban-run-raw/4553754001/">owning these animals as pets</a>. Their concerns range from reptiles posing a serious danger to public health to beliefs about reptiles being too cold to love. Why do reptiles get a bad rap?</p>
<h2>Reptile-borne diseases</h2>
<p>Critics of reptile pet ownership often state that <a href="https://arav.org/salmonella-bacteria-reptiles/">reptiles are riddled with diseases</a>, and while it is true that reptiles do harbour disease, the risk is often far lower than people realize. This fear may be due to outbreaks of salmonella in people that occurred nearly half a century ago: In the 1970s, turtles suddenly became a popular pet, and reptile-borne salmonella incidences increased, representing about <a href="https://doi.org/10.1093/oxfordjournals.aje.a121418">11 per cent of all human cases</a>. </p>
<p>In North America, people are more likely to acquire salmonella from consuming animal products. Education campaigns and legislation in the 1990s led to a significant reduction in reptile-borne salmonella, <a href="https://dx.doi.org/10.3201/eid2207.150685">decreasing it to just six per cent of cases</a>. </p>
<p>However, close study of reptile-caused illnesses in humans has only examined trends up to the early 2000s, so public health data may be subject to change <a href="https://doi.org/10.2807/1560-7917.ES.2016.21.34.30324">as reptiles increase in popularity</a>.</p>
<p>Interestingly, although diseases are highlighted as a reason to avoid pet reptiles, pet mammals like dogs and cats have been repeatedly linked to a variety of health problems, <a href="https://avmajournals.avma.org/doi/pdf/10.2460/javma.252.8.945">such as rabies</a> <a href="https://asthma.ca/get-help/asthma-triggers/pets-asthma/">and asthma</a>. Yet these dangers are deemed acceptable by society, despite the public health risks (<a href="https://www.healthlinkbc.ca/health-topics/hw181108">rabies is incurable and fatal</a>).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/417106/original/file-20210819-15-egca5x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A turtle with a red streak on its head surrounded by greenery" src="https://images.theconversation.com/files/417106/original/file-20210819-15-egca5x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/417106/original/file-20210819-15-egca5x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/417106/original/file-20210819-15-egca5x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/417106/original/file-20210819-15-egca5x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/417106/original/file-20210819-15-egca5x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/417106/original/file-20210819-15-egca5x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/417106/original/file-20210819-15-egca5x.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">Turtles, like this red-eared slider, became popular as household pets in the 1970s.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<h2>Companionship and entertainment</h2>
<p>Another common critique is that reptiles simply do not make good pets. This belief stems from the view that reptiles are lumbering, boring creatures. However, <a href="https://doi.org/10.1136/vr.104296">this could not be further from the truth</a>. </p>
<p>There are some incredible examples of reptile nimbleness. For example, <a href="https://jhupbooks.press.jhu.edu/title/secret-social-lives-reptiles">basilisks can run on two legs on the surface of water for more than 20 metres, and crocodiles can use their massive jaws to delicately move their babies and eggs without damaging them</a>. Some lizards can <a href="https://doi.org/10.1098/rsbl.2011.0480">solve food puzzles</a> and <a href="https://doi.org/10.1007/s10071-014-0803-7">tortoises and bearded dragons can take cues from others of the same species to speed up problem-solving tasks</a>, both of which are abilities <a href="http://doi.org/10.1093/oxfordhb/9780199738182.013.0008">once thought to be present only in birds and mammals</a>. </p>
<p>While affection is harder to prove using current scientific methods, <a href="https://doi.org/10.19227/jzar.v9i2.540">tests have shown that some tortoises</a> (likely dependent on personality) <a href="https://doi.org/10.1002/zoo.21227">prefer having their shells scratched by familiar humans</a> to food or toys when making a choice.</p>
<h2>Reptile welfare</h2>
<p>Beyond the risks for people, owning a reptile does pose some threat to the animals themselves. While there is no evidence that <a href="https://doi.org/10.1136/vr.104296">reptiles suffer disproportionately poor welfare compared to other pets</a>, it is easy to access misleading and conflicting information online. Well-intentioned owners can end up keeping reptiles in substandard conditions, <a href="https://doi.org/10.1136/vr.k4836">eventually causing a variety of preventable health issues</a>. </p>
<p>Due to their ectothermic (cold-blooded) nature, reading body language can be tricky, making it difficult to tell when reptiles are suffering. Making things worse, reptiles can often endure severe health conditions longer than mammals. Ultimately, this means that <a href="https://www.chippingnortonvets.co.uk/uploads/Factors%20contributing%20to%20poor%20welfare%20of%20pet%20reptiles.pdf">reptiles can be kept in neglectful conditions for months, or even years</a>. </p>
<p>Thankfully, some <a href="https://www.facebook.com/groups/AdvancingHerpHusbandry/">reptile welfare groups on social media</a> are doing their best to collect and communicate the most up-to-date standards of reptile care. Herpetologists — who study reptiles and amphibians — are <a href="https://doi.org/10.1016/j.applanim.2021.105324">continually refining</a> the best husbandry practices and methods for evaluating reptile welfare. </p>
<h2>Reptile abuse</h2>
<p>Outdated beliefs about reptiles, often spurred on by a misguided distrust, can do real harm by allowing reptile mistreatment to persist. For example, perhaps one of the most astonishingly cruel reptile-related practices are the <a href="https://www.biologicaldiversity.org/campaigns/outlawing_rattlesnake_roundups/index.html">annual rattlesnake rodeos taking place in the southern United States</a>. </p>
<p>Rattlesnakes are taken from the wild and stored for up to eight months, usually without food, water or regular cage maintenance. If the snakes survive this process, <a href="https://commonreader.wustl.edu/c/beauty-and-the-beast-at-the-worlds-largest-rattlesnake-roundup/">they are brought to the rodeo where they are physically beaten, taunted, stomped on or hastily decapitated all while fully conscious</a>. </p>
<p>The manner in which snakes are treated at these events would cause mass outrage if the same practices were performed on any mammal or bird — so why is it acceptable for a reptile? </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/U6TfBBN8vqs?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A National Geographic story on the Sweetwater, Texas, rattlesnake roundup.</span></figcaption>
</figure>
<h2>Championing reptiles</h2>
<p>Perhaps, through the proper ownership of reptiles as pets, and by dispelling the myths surrounding them, <a href="https://doi.org/10.3390/ani9100821">we can raise awareness of their cognitive abilities and better appreciate their unique appeal</a>.</p>
<p>Though often overlooked, reptiles can make incredible pets. Many owners find themselves captivated by their stoic beauty, and others find even the simplest behaviour endearing. With proper education, owners are able to care for a pet reptile for many years in a way that ensures the health of both the animal and their owner.</p>
<p>Pet ownership may inspire positive change for the welfare of reptiles, putting an end to inhumane practices and promoting conservation goals <a href="http://doi.org/10.12966/abc.08.01.2015">for one of the most underfunded and under-researched groups of animals</a>. </p>
<p>In light of all this, perhaps it is time we show some warmth to our cold-blooded companions.</p><img src="https://counter.theconversation.com/content/166257/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Melanie Denomme receives support from Natural Sciences and Engineering Research Council of Canada given to Glenn Tattersall.</span></em></p><p class="fine-print"><em><span>Glenn Tattersall receives funding from Natural Sciences and Engineering Research Council of Canada. </span></em></p>Reptiles get a bad rap, but this is because they’re misunderstood. Promoting healthy reptile pet ownership can contribute to conservation and education efforts.Melanie Denomme, PhD Student, Biological Sciences, Brock UniversityGlenn J Tattersall, Professor, Biological Sciences, Brock UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1576332021-03-28T08:49:48Z2021-03-28T08:49:48ZWhat Madagascar’s amazing mini creatures tell us about evolution<figure><img src="https://images.theconversation.com/files/392048/original/file-20210327-21-1lcbjx6.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Brookesia tedi, described in 2019, is one of the smallest chameleons, and indeed one of the smallest amniote vertebrates, on earth. </span> <span class="attribution"><span class="source">Mark D. Scherz</span></span></figcaption></figure><p><em>Madagascar has many “mini” creatures. These include a recently discovered group of miniaturised frogs as well as the discovery earlier this year of the <a href="https://www.bbc.com/news/world-africa-55945948">smallest reptile on earth</a> – the Brookesia nana, or nano-chameleon, which is the size of a paperclip. Moina Spooner, from The Conversation Africa, asked Dr Mark D. Scherz, an amphibian and reptile specialist who focuses on Madagascar, to explain what causes these animals to miniaturise.</em></p>
<h2>Which miniaturised species have been discovered recently?</h2>
<p>Madagascar is famous for its small animals; the mouse lemurs, the smallest primates on earth, for instance, are widely known. There’s also growing awareness that Madagascar is home to a variety of other uniquely miniaturised animals, especially chameleons and frogs. In those groups, researchers have discovered large numbers of tiny species in recent years. </p>
<p>In 2017, researchers described 26 species of <em>Stumpffia</em> – a group of frogs – the smallest of which is not even 1cm long at adult body size. It is one of the smallest frogs in the world. </p>
<figure class="align-center ">
<img alt="Frog on a leaf with a human finger next to it to show relative size" src="https://images.theconversation.com/files/391646/original/file-20210325-15-1lsr12z.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/391646/original/file-20210325-15-1lsr12z.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=454&fit=crop&dpr=1 600w, https://images.theconversation.com/files/391646/original/file-20210325-15-1lsr12z.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=454&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/391646/original/file-20210325-15-1lsr12z.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=454&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/391646/original/file-20210325-15-1lsr12z.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=571&fit=crop&dpr=1 754w, https://images.theconversation.com/files/391646/original/file-20210325-15-1lsr12z.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=571&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/391646/original/file-20210325-15-1lsr12z.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=571&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Stumpffia yanniki, a moderately small narrow-mouthed frog species from northern Madagascar, described in 2017.</span>
<span class="attribution"><span class="source">Mark D. Scherz</span></span>
</figcaption>
</figure>
<p>Then, in 2019, my colleagues and I showed that several different groups of cophyline microhylids – a group of narrow-mouthed frogs that are only found in Madagascar – have become miniaturised independently. One group of these was an entirely new genus. We gave them the fitting name “<em>Mini</em>”, with the three species <em>Mini mum</em>, <em>Mini scule</em>, and <em>Mini ature</em>. </p>
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Read more:
<a href="https://theconversation.com/meet-the-mini-frogs-of-madagascar-the-new-species-weve-discovered-113946">Meet the mini frogs of Madagascar -- the new species we've discovered</a>
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<p>We have also found some new tiny chameleons. In 2019, we described <a href="https://zse.pensoft.net/article/32818/"><em>Brookesia tedi</em></a>, a chameleon that reaches a total length of just 32mm. And then in early 2021, we described <a href="https://www.nature.com/articles/s41598-020-80955-1"><em>Brookesia nana</em></a>, the smallest chameleon, which has adult males of just 21.6mm total length, and females 28.9mm.</p>
<h2>Why have they evolved to be so small?</h2>
<p>There are probably many different reasons why these animals have evolved to be so small. For instance, it might be possible for them to exploit new resources that weren’t previously available to them. This may be new food sources, or exploring the space between leaves and tree roots that is inaccessible to larger animals. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/391413/original/file-20210324-23-pwx674.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/391413/original/file-20210324-23-pwx674.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/391413/original/file-20210324-23-pwx674.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/391413/original/file-20210324-23-pwx674.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/391413/original/file-20210324-23-pwx674.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/391413/original/file-20210324-23-pwx674.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/391413/original/file-20210324-23-pwx674.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">Stumpffia madagascariensis is a tiny leaf-litter dwelling frog from northern Madagascar.</span>
<span class="attribution"><span class="source">Mark D. Scherz</span></span>
</figcaption>
</figure>
<p>It could also be driven by competition with other, similar species. Species may diverge into different size categories to partition their resources and avoid direct competition.</p>
<p>In many cases, there may be no strong or single selective force that is driving the miniaturisation at all, but instead it could simply be a process of random change in the population, which occurs in all organisms over time. This is further driven by population bottlenecks as the smaller and smaller animals get cut off from other populations. </p>
<p>The simple answer is that we just don’t know yet in any of the cases, and it is likely that in most it is a combination of factors. We are much better able to say what the correlates of miniaturisation are – that is, the suite of features, behaviours, and ecologies that accompany miniaturisation – than the causes.</p>
<h2>Does Madagascar have an unusually high number of mini creatures?</h2>
<p>Speaking only of reptiles and amphibians, maybe, but it is hard to say for sure. South-East Asia has <a href="https://www.nationalgeographic.com/animals/article/120111-smallest-frogs-vertebrates-new-species-science-animals">a massive diversity of miniaturised frogs</a>, for instance, but whether the number of major miniaturisation events in that region is greater or less than in Madagascar is difficult to say for sure. </p>
<p>The same goes for Central and South America, where there are plenty of tiny amphibians and reptiles, including salamanders, frogs and lizards. </p>
<p>Ultimately, even though Madagascar may not be the world champion in terms of the number of miniaturised reptiles and amphibians, I think it does stand out as an exceptionally interesting place in which to study their evolution, and we are only just starting to scratch the surface of this.</p>
<h2>What does their tiny size tell us about evolutionary processes?</h2>
<p>This is the question I find the most exciting. From miniaturisation we can learn all kinds of interesting things about physiology, evolution and biomechanics – how organisms move and function.</p>
<p>For instance, there appears to be a pattern where the evolution of miniaturisation is associated with changes in ecology. Almost all miniaturised frogs in Madagascar are terrestrial, irrespective of whether their ancestors were terrestrial arboreal (living in trees). The only conditions under which miniaturised frogs have remained arboreal throughout miniaturisation has been when they reproduce in the water cavities at the base of certain plants’ leaves, such as the <em>Pandanus</em> plant.</p>
<p>We have also learned that the microhylid frogs of Madagascar have mostly miniaturised by retaining juvenile-like characteristics, known as paedomorphosis. For instance, they all have relatively large heads and eyes for their body sizes.</p>
<p>But one species, <em>Rhombophryne proportionalis</em>, has apparently miniaturised by proportional dwarfism. It has the approximate proportions of a non-miniaturised Rhombophryne. So, although paedomorphosis may be the typical way that Malagasy frogs miniaturise, it is by no means the only way that they can miniaturise. </p>
<p>Another particularly interesting finding is that miniaturisation has apparently evolved again and again in different lineages. This was already evident in frogs at the global scale (there are miniaturised frog lineages throughout the tropics). But one group of frogs in Madagascar has done this five or more times alone. This tells us that the evolution of miniaturisation can occur frequently and may be advantageous under certain circumstances. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/391412/original/file-20210324-23-hbq4me.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/391412/original/file-20210324-23-hbq4me.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/391412/original/file-20210324-23-hbq4me.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/391412/original/file-20210324-23-hbq4me.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/391412/original/file-20210324-23-hbq4me.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/391412/original/file-20210324-23-hbq4me.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/391412/original/file-20210324-23-hbq4me.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">Brookesia tuberculata from northern Madagascar was for some time held to be the smallest species of chameleon, but has been repeatedly upstaged. Its real claim to fame, however, is that it has by far the largest hemipenis relative to its body length of any chameleon.</span>
<span class="attribution"><span class="source">Mark D. Scherz</span></span>
</figcaption>
</figure>
<p>From our work on miniaturised chameleons, we have also found that, as these lizards shrink, their genitals increase in relative size. We think that this is because the females are larger than the males. Because the male genitals must couple with those of the females for successful reproduction, and because the female is not as small as the male, the male’s genitals are constrained to remain proportional to the size of the female, even while his body size evolves to be smaller.</p>
<p>There are hundreds of open questions in the field of tiny vertebrate studies. We are just beginning to understand how widespread and common this trait is, how many species have done it, and how many miniaturised species remain undescribed. There is a whole miniature frontier of interesting research to be had among these tiny vertebrates, and I, for one, am excited to see what we discover next.</p><img src="https://counter.theconversation.com/content/157633/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark D. Scherz 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>Madagascar stands out as an exceptionally interesting place in which to study the evolution of “mini” creatures. And we are only just starting to scratch the surface of this.Mark D. Scherz, Research scientist, Technical University BraunschweigLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1545782021-02-24T11:11:34Z2021-02-24T11:11:34ZHow we turned a golf course into a haven for rare newts, frogs and toads<figure><img src="https://images.theconversation.com/files/385907/original/file-20210223-14-cnfbpy.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4992%2C3325&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/common-frog-rana-temporaria-single-reptile-167747600">Erni/Shutterstock</a></span></figcaption></figure><p>Around two in five amphibian species are <a href="https://www.iucnredlist.org/">threatened with extinction</a> around the world. In Britain, all of our native frog, toad and newt species have <a href="https://www.newnaturalists.com/products/amphibians-reptiles-collins-new-naturalist-library-book-87-9780007308620/">declined since 1945</a>, with one species – <a href="https://www.arc-trust.org/pool-frog">the pool frog</a> – dying out in the 1990s. Climate change, disease and invasive species all have a hand in this, but one of the greatest <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14739">pressures</a> facing amphibians is the loss of their habitat. As more land is developed for houses, roads and shops, those wild and marshy patches where amphibians thrive are scrubbed from maps.</p>
<p>Setting aside land in nature reserves can help protect biodiversity, though on their own, these islands of natural habitat cannot provide enough space to revive wider communities of wildlife. Since much of the UK’s land is <a href="https://www.countryfile.com/news/who-owns-england-history-of-englands-landownership-and-how-much-is-privately-owned-today/">in private hands</a>, conservationists need to think about how nature can be encouraged on land occupied by businesses, including farms, estates and golf courses.</p>
<p>We are two ecologists who are dedicated to restoring habitats for amphibians wherever we can. By working with land managers of all kinds, we’re figuring out how to repopulate modern landscapes with these creatures. Here’s what we’ve learned so far.</p>
<h2>Getting landowners onside</h2>
<p>Perhaps the most famous amphibians in literature are the unfortunate newts and frogs of Shakespeare’s Macbeth, which end up in the witches’ brew on <a href="https://forreslocal.com/visiting/what-to-see-and-do-in-forres/macbeth/">Forres heath</a> in the Scottish Highlands. Over 400 years later, <a href="https://link.springer.com/article/10.1007/s10344-014-0863-7">our own research</a> has shown that populations of great-crested newts face a different kind of toil and trouble. </p>
<p>For centuries, ponds existed on British farmland to water livestock, which offered habitats for amphibians to breed in. But nowadays, sheep and cattle drink from troughs and many wetlands which once sustained wildlife have been drained to create timber plantations and golf courses.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/384495/original/file-20210216-13-5pe7qu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A large and speckled newt on dry soil." src="https://images.theconversation.com/files/384495/original/file-20210216-13-5pe7qu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/384495/original/file-20210216-13-5pe7qu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=480&fit=crop&dpr=1 600w, https://images.theconversation.com/files/384495/original/file-20210216-13-5pe7qu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=480&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/384495/original/file-20210216-13-5pe7qu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=480&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/384495/original/file-20210216-13-5pe7qu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=604&fit=crop&dpr=1 754w, https://images.theconversation.com/files/384495/original/file-20210216-13-5pe7qu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=604&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/384495/original/file-20210216-13-5pe7qu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=604&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 Highland great-crested newt.</span>
<span class="attribution"><span class="source">David O’Brien</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Any plan to halt the decline of Britain’s amphibians must be compatible with different types of land use. So in 2014, we sat down with people working in forestry, farming and a local golf club to develop a plan for <a href="https://besjournals.onlinelibrary.wiley.com/doi/10.1002/2688-8319.12038">restoring 25 ponds</a> in the Scottish Highlands, focusing on Forres and the areas around Inverness which have seen the greatest loss of ponds.</p>
<p>Rather than imposing rules on land managers, we talked with them about their interests and what they saw as important. Pride in their heritage and the opportunity to be seen as good stewards of the land were what most motivated those we spoke to. </p>
<p>One of the sites had been in the owner’s family since the 17th century, and the farmers felt a connection to their land and the wildlife that lived on it. “I may never notice the newts in the pond,” one said. “But I’m glad to know they’re there.”</p>
<p>The golf pro, who had grown up near the course where he now worked, remembered catching newts and tadpoles as a child and wanted his grandchildren to be able to see them too. He used his influence with the club committee to convince them that a pond wouldn’t just be good for nature, but would improve the appearance of the course. </p>
<p>The ground staff joined in to manage vegetation around the ponds to ensure places for the animals to feed outside of the breeding season. Whenever we now survey this pond for species, we’re greeted by golfers who’re proud of “their frogs and newts” and want to know how they’re doing.</p>
<h2>Creating the perfect pond</h2>
<p>We had permission to start restoring habitats on private land, but how can you tell if what you’re making is right for the species you’re trying to help? Luckily, we had a pretty good idea of what makes the perfect pond because we had 25 years’ worth of data gathered by citizen scientists, as well as <a href="https://link.springer.com/article/10.1007%2Fs10750-016-3053-7">our own observations</a> of ponds filled with amphibians. </p>
<p>Everything from the slope of the nearby bank, the presence of fish and insects and the kind of plants which fringed the pool were carefully considered. We then designed ponds ideal for all five amphibian species native to the Scottish Highlands – the common frog, common toad, and smooth, palmate and great-crested newts.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/384494/original/file-20210216-13-1vaj7ed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A pond amid a boggy scrubland with trees in the background." src="https://images.theconversation.com/files/384494/original/file-20210216-13-1vaj7ed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/384494/original/file-20210216-13-1vaj7ed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/384494/original/file-20210216-13-1vaj7ed.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/384494/original/file-20210216-13-1vaj7ed.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/384494/original/file-20210216-13-1vaj7ed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/384494/original/file-20210216-13-1vaj7ed.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/384494/original/file-20210216-13-1vaj7ed.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"></a>
<figcaption>
<span class="caption">One of the first new ponds to be colonised, which now has breeding common frogs and three newt species.</span>
<span class="attribution"><span class="source">David O’Brien</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Newts rarely travel more than a few hundred metres, and if the nearest pond is further away or if there’s a barrier like a busy road, they won’t be able to move between ponds. This can lead to inbreeding and leave populations vulnerable to extinction. If a pond dries up for several breeding seasons then it won’t be recolonised once it’s refilled with water. For this reason, we restored former ponds and created new ones close to occupied ponds.</p>
<p><a href="https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1002/2688-8319.12038">Five years on</a>, 24 out of the 25 ponds are inhabited by amphibians. After surveying our ponds and comparing them with 88 long-established ones in the area, we were delighted to find that not only were all five species breeding in them, including the locally rare great-crested newt, but on average our ponds held more species than the pre-existing ones. We’ve stayed in contact with all the land managers and they remain committed to conservation. </p>
<p>And the one pond with no amphibians? Unfortunately, an error led us to construct a pond that wasn’t quite right. But we accidentally created the perfect pond for a rare dragonfly called the white-faced darter instead. Now we can’t wait to find out what other species might have made our ponds their homes.</p><img src="https://counter.theconversation.com/content/154578/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David O'Brien works for NatureScot (formerly Scottish Natural Heritage) which funded part of this project alongside Forestry and Land Scotland.</span></em></p><p class="fine-print"><em><span>Robert Jehle 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>Britain’s native amphibians are in steep decline thanks to wetlands disappearing and ponds drying up.David O'Brien, PhD Candidate in Wildlife Biology, University of SalfordRobert Jehle, Reader in Population Biology, University of SalfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1494182020-11-06T15:20:54Z2020-11-06T15:20:54ZA skin-eating fungus from Europe could decimate Appalachia’s salamanders – but researchers are working to prevent an outbreak<figure><img src="https://images.theconversation.com/files/367572/original/file-20201104-13-sy3ipj.jpg?ixlib=rb-1.1.0&rect=634%2C0%2C3354%2C2012&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The red salamander (_Pseudotriton ruber_) is a species endemic to the United States</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/black-lipped-salamander-sitting-on-a-moss-covered-royalty-free-image/499305760">Betty4240/iStock via Getty Images</a></span></figcaption></figure><p>The Southern Appalachian mountains are a global <a href="https://doi.org/10.1371/journal.pone.0012189">biodiversity hot spot</a> for salamanders. Dr. Deb Miller and Dr. Matt Gray lead the Amphibian Disease Laboratory at the University of Tennessee and are <a href="https://youtu.be/rT3HTTd84gY">looking at various strategies</a> to prevent a fungus that is deadly to salamanders from entering the U.S. via the international pet trade. They are also conducting research to learn more about the disease, and looking at potential strategies to reduce the spread of the fungus in case it does enter the country._</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/rT3HTTd84gY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Deb Miller and Matt Gray talk about the Bsal fungus and their efforts to protect salamanders.</span></figcaption>
</figure>
<h2>Why do the Appalachian mountains have so many salamanders?</h2>
<p>The intersection of North Carolina, Tennessee and Georgia is a global biodiversity hot spot for salamanders. Tennessee, for example, has around 60 species, more than the entire continent of Europe. </p>
<p>The southern Appalachian Mountain Range is one of the oldest mountain ranges in the world, so there has been a lot of opportunity for many species to evolve over a long period of time. The temperate conditions and high elevations create a forest system with lots of moisture and accumulated leaf litter. Over time, that creates the perfect habitat for salamanders. </p>
<h2>What is the fungus that threatens the salamanders?</h2>
<p>Batrachochytrium salamandrivorans, or Bsal, is the second chytrid fungus that has been discovered. The first chytrid fungus that many people have heard about is called Batrachochytrium dendrobatidis, or Bd, and that’s been associated with the decline of over 500 amphibian species globally and over 100 species extinctions. </p>
<p>Bsal fungus specifically attacks the outer covering of a salamander’s skin, but we are finding that it can attack frog skin as well. The skin is one of the most important organs in an amphibian’s body. It is so important because some salamanders don’t have lungs, and so the skin is a major source for respiration for them. It also maintains the right amount of hydration so that their body systems, including their heart, can function properly. </p>
<p>The name salamandrivorans literally means that it eats the salamander. In actuality, it destroys the skin with a coating of fungus. The skin stops functioning, and the animal shuts down and dies.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/367824/original/file-20201105-22-dbbq8r.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/367824/original/file-20201105-22-dbbq8r.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/367824/original/file-20201105-22-dbbq8r.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/367824/original/file-20201105-22-dbbq8r.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/367824/original/file-20201105-22-dbbq8r.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/367824/original/file-20201105-22-dbbq8r.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/367824/original/file-20201105-22-dbbq8r.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/367824/original/file-20201105-22-dbbq8r.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">Color-inverted photo of a green salamander (Aneides aeneus), which is a species of greatest conservation concern in several Appalachian states and is highly susceptible to Bsal.</span>
<span class="attribution"><span class="source">Todd Amacker Conservation Visuals</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>The fungus hasn’t yet entered North America, but what was its effect on amphibians in Europe?</h2>
<p>The discovery of a new chytrid fungus in Northern Europe was very alarming. It was discovered in 2010, and since then, salamander populations all over Europe have seen <a href="https://www.sciencemag.org/news/2017/07/fungus-attacking-europe-s-most-beloved-salamander-it-could-wreak-havoc-if-it-gets-north">precipitous declines</a>. There’s now research that indicates that it may have actually been introduced around Germany and spread out from there. </p>
<p>It has been found in Southeast Asia infecting salamanders but having no effects on them. It seems to live with the salamanders there. But it is believed to have been introduced to Europe through the international pet trade. We have not detected Bsal yet here in North America, or any place in the Western Hemisphere, but we are concerned that the pet trade is the most likely route for introduction here.</p>
<h2>What are the steps being taken to prevent it from entering the US?</h2>
<p>The United States has been fairly proactive in its response to Bsal. The US Fish and Wildlife Service passed a <a href="https://www.usgs.gov/centers/nwhc/science/batrachochytrium-salamandrivorans-bsal?qt-science_center_objects=0#qt-science_center_objects">moratorium</a> in 2016 on the importation of around 200 species of salamanders that could serve as possible hosts to Bsal. That effectively stopped most of the salamander trade coming into our country. However, since then, we’ve learned that frogs can become infected with Bsal too, which constitute 95% of trade, so the threat of introduction to the U.S. remains. </p>
<p>There has been very limited surveillance for Bsal out in the pet industry, and we’re working on partnerships that would expand sampling for Bsal. It’s also in the industry’s interest because it threatens the captive populations and their profits. </p>
<h2>What is your research focusing on?</h2>
<p>With regard to pathology, we’re looking at a few different things. One, what does it do to the body other than taking away the skin? What is the critical point at which we might be able to do something? And are there bacteria or other opportunistic pathogens playing a role in the sickness?</p>
<p>In terms of research on transmission and disease intervention strategies, we’ve been looking at what happens if it gets into a pond system here. Could we go into that pond system and reduce the density of the salamanders, just as humans are doing with social distancing during the pandemic?</p>
<p>Bsal spreads through water, but also direct contact, and so we reduce that ability for either the pathogen to swim or for salamanders to bump into each other by increasing the number of plants around their habitat, and hence the habitat complexity.</p>
<p>We also are looking at plant-derived <a href="https://doi.org/10.1038/srep11788">fungicides</a>. Salamander skin has lots of natural microbes on it, and we’re trying to <a href="https://doi.org/10.1016/j.tim.2015.12.010">supplement their natural microbiome</a> on their skin to help in the defense of this pathogen. So we collaborate with colleagues from several universities to investigate all of those questions.</p>
<h2>What role do salamanders play in this ecosystem?</h2>
<p>It’s been estimated that in a typical pond system, amphibians can consume over a million insects in a year, including mosquitoes. They consume adults as well as larvae before they can bite you or transmit a zoonotic disease. Both tadpoles and salamander larvae love to eat the little mosquito larvae, which are very nutritious. They play a similar role to that of bats in the air.</p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p><img src="https://counter.theconversation.com/content/149418/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Debra Miller and Matt Gray received funding from National Science Foundation-Ecology and Evolution of Infectious Diseases Program and a U.S. Fish and Wildlife Service Competitive State Wildlife Grant administered through the Southeastern Association of Fish and Wildlife Agencies and Tennessee Wildlife Resources Foundation. Additional funds for their Bsal research was received by the BAND Foundation, North Carolina Wildlife Resources Commission, Tennessee Wildlife Resources Agency and Liquid Spark, Inc. Matt Gray is Past Chair of the North American Bsal Task Force and Past Director of Global Ranavirus Consortium, Inc.
Debra Miller is past-president of the Wildlife Disease Association and is a co-chair of the herpetofaunal disease task team of the Southeast Partners in Amphibian and Reptile Conservation.</span></em></p><p class="fine-print"><em><span>Matt Gray does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The Bsal fungus is not yet here in North America, or any place in the Western Hemisphere, but there is concern that the pet trade is the most likely route for introduction here.Debra Miller, Professor, University of TennesseeMatt Gray, Professor, University of TennesseeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1494452020-11-05T19:06:42Z2020-11-05T19:06:42ZThis tiny amphibian that outlived the dinosaurs provides the earliest example of a rapid-fire tongue<p>Albanerpetontids, or “albies” for short, are the cute little salamander-like amphibians you’ve likely never heard of.</p>
<p>Now extinct, Albies had a dream run. They’d been around since the Middle Jurassic around 165 million years ago, and probably even earlier. They lived through the age of dinosaurs (and saw out their extinction), then lived through the rise of the great apes, before quietly disappearing about 2.5 million years ago.</p>
<p>Albie fossils are scattered across continents, including in Japan, Morocco, England, North America, Europe and Myanmar. But until recently, we knew relatively little about what they looked like or how they lived. </p>
<p><a href="https://science.sciencemag.org/content/370/6517/687">New research</a> by my colleagues and I, published today in Science, reveals these amphibians were the earliest known creatures to have rapid-fire tongues. This also helps explain why albies were once misidentified as chameleons. </p>
<h2>A miniature marvel uncovered</h2>
<p>The reason albies remained largely elusive until recently is because they were tiny. Their slight, fragile bones are usually found as isolated jaw and skull fragments, making them hard to study. </p>
<p>The first almost complete albie specimen was found in the wetland environment deposits of Las Hoyas, Spain, and <a href="https://www.nature.com/articles/373143a0">reported in 1995</a>. Even though it was squashed flat, it was enough for palaeontologists to conclude albies were unlike any living salamander or any other amphibian.</p>
<p>They were completely covered in scales like reptiles, had highly flexible necks like mammals, an unusual jaw joint and large eye sockets suggesting good vision. Why were albies so unique?</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/meet-the-super-salamander-that-nearly-ate-your-ancestors-for-breakfast-39221">Meet the super salamander that nearly ate your ancestors for breakfast</a>
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<h2>Mistakes do happen</h2>
<p>The answer partly came to light in 2016, when a group of researchers <a href="https://advances.sciencemag.org/content/2/3/e1501080">published a paper</a> demonstrating the diversity of lizards found in the <a href="https://www.livescience.com/29231-cretaceous-period.html">Cretaceous</a> forests of what is now Myanmar. </p>
<p>They presented a dozen tiny 99-million-year-old “lizards”, all preserved in amber. Some were even found with soft tissue remains such as skin, claws and muscles, still attached within the fossilised tree resin. </p>
<p>The researchers used “<a href="https://www.microphotonics.com/what-is-micro-ct-an-introduction/">micro-CT</a>” technology to digitally excavate and study the specimens in detail. This involved using 3D imaging to digitally remove the fossil from the amber and study it on a computer — a technique that avoids the risk of physically damaging the fossil.</p>
<p>They noticed one small, juvenile specimen had a long rod-shaped tongue bone. It was identified as the earliest known chameleon: a remarkable discovery! Or was it?</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/z3oh73amxQo?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">See a chameleon’s rapid-fire tongue in attack mode. (BBC Earth)</span></figcaption>
</figure>
<p>Alas, mistakes do happen in science. As lizard experts, the researchers had interpreted their results through this lens. It took the keen eye of Susan Evans, a professor of vertebrate morphology and palaeontology at University College London, to recognise this particular “lizard” was actually a misidentified albie.</p>
<h2>A tongue-tying revelation</h2>
<p>Some time later, Sam Houston State University assistant professor Juan Daza spotted another unbelievable specimen among a collection of fossils preserved in <a href="https://www.researchgate.net/publication/318588578_A_catalogue_of_Burmite_inclusions">Burmite amber</a>, <a href="http://vertpaleo.org/Membership/Member-Ethics/Guidelines-from-the-Ethics-Committee.aspx">ethically sourced</a> from Myanmar’s Kachin state.</p>
<p>It was an adult version of the juvenile albie Evans identified. Needing higher-resolution 3D images, the sample was sent to me to study at the Australian Nuclear Science and Technology Organisation’s <a href="https://www.ansto.gov.au/research/facilities/australian-synchrotron/overview">Australian Synchrotron</a> in Melbourne.</p>
<p>Named after a class of mythical spirits responsible for guarding natural treasures, Yaksha, and the person who discovered the fossil, Adolf Peretti (founder of the non-profit <a href="https://www.pmf.org/">Peretti Museum Foundation</a>) — the <em>Yaksha perettii</em> specimen was an entire skull trapped in golden amber. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/367658/original/file-20201105-20-1fvtl1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Specimen preserved in amber." src="https://images.theconversation.com/files/367658/original/file-20201105-20-1fvtl1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/367658/original/file-20201105-20-1fvtl1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=622&fit=crop&dpr=1 600w, https://images.theconversation.com/files/367658/original/file-20201105-20-1fvtl1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=622&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/367658/original/file-20201105-20-1fvtl1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=622&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/367658/original/file-20201105-20-1fvtl1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=781&fit=crop&dpr=1 754w, https://images.theconversation.com/files/367658/original/file-20201105-20-1fvtl1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=781&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/367658/original/file-20201105-20-1fvtl1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=781&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 <em>Yaksha perettii</em> specimen is preserved in amber. The fossil was studied without being removed.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Quick hits to unsuspecting prey</h2>
<p>Its features that stood out were a long bone projecting back out of the mouth and soft tissue remains, including part of the tongue, jaw muscles and eyelids. By sheer luck, the soft tissue remains proved the long bone in the mouth was directly attached to the tongue. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/367659/original/file-20201105-15-1ha34bq.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Computer rendering of the _Yaksha perettii_ specimen" src="https://images.theconversation.com/files/367659/original/file-20201105-15-1ha34bq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/367659/original/file-20201105-15-1ha34bq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=414&fit=crop&dpr=1 600w, https://images.theconversation.com/files/367659/original/file-20201105-15-1ha34bq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=414&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/367659/original/file-20201105-15-1ha34bq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=414&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/367659/original/file-20201105-15-1ha34bq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=520&fit=crop&dpr=1 754w, https://images.theconversation.com/files/367659/original/file-20201105-15-1ha34bq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=520&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/367659/original/file-20201105-15-1ha34bq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=520&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 rendering of the <em>Yaksha perettii</em> skull shows the extinct amphibian’s soft tissue and projectile tongue apparatus (in orange).</span>
<span class="attribution"><span class="source">Edward Stanley/Florida Museum of Natural History</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In other words, <em>Y. perettii</em> was a predator armed with an incredible weapon: a specialised ballistic tongue that fired at lightning speed to capture prey — just as chameleons do today. It’s no wonder the original juvenile, only 1.5 centimetres long, was initially mistaken for a chameleon.</p>
<p>Modern chameleons have accelerator muscles in their tongues that lock in stored energy. This lets them fire their tongues at speeds of up to <a href="https://www.sciencemag.org/news/2016/01/video-chameleon-has-one-fastest-tongues-animal-kingdom">100 kilometres per hour</a> in just a fraction of a second. </p>
<p>We believe albies’ projectile tongues were just as fast, used to great effect while sitting motionless in trees or on the ground. If so, this also explains why albies had unusual jaw joints, flexible necks and large, forward-facing eyes. All these traits would have made up their predator toolkit.</p>
<h2>Tree sap turned to iridescent amber</h2>
<p>Despite these remarkable new insights, however, many mysteries of albanerpetontids remain. For instance, how exactly are they related to other amphibians? How did they survive for so long, only to die out relatively recently? </p>
<p>We’ll need more intact specimens to answer these questions. And most of these specimens will probably come from the <a href="https://www.newscientist.com/article/mg24232280-600-blood-amber-the-exquisite-trove-of-fossils-fuelling-war-in-myanmar/">Hukawng Valley</a> in Kachin, Myanmar. </p>
<p>It’s expected about 100 million years ago this region was an island covered in vast forests. Global temperatures back then would have exceeded today’s, with trees producing vast amounts of resin (which later turned into amber) as a result of damage by insects and fire. </p>
<p>Amber studied from this region will not only increase our knowledge of its expired ecosystems, it could also provide insight into how certain organisms today might evolve in response to a warming climate.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/fossil-footprints-give-glimpse-of-how-ancient-climate-change-drove-the-rise-of-reptiles-69067">Fossil footprints give glimpse of how ancient climate change drove the rise of reptiles</a>
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<img src="https://counter.theconversation.com/content/149445/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Joseph Bevitt 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>If albanerpetontids were around today, they’d easily fit in your hand. And although their bones are found all over the world, these unique amphibians eluded experts for a long time.Joseph Bevitt, Senior Instrument Scientist, Australian Nuclear Science and Technology OrganisationLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1493712020-11-05T15:30:14Z2020-11-05T15:30:14ZThe diet of invasive toads in Mauritius has some rare species on the menu<figure><img src="https://images.theconversation.com/files/367196/original/file-20201103-19-1edoc5o.JPG?ixlib=rb-1.1.0&rect=5%2C379%2C1268%2C549&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The invasive guttural toad.</span> <span class="attribution"><span class="source">Author supplied.</span></span></figcaption></figure><p>The <a href="https://www.sanbi.org/animal-of-the-week/guttural-toad/">guttural toad</a> (<em>Sclerophrys gutturalis</em>) is a common amphibian found in much of sub-Saharan Africa, from Angola to Kenya and down to eastern South Africa. With such a wide geographic range, and a liking for living in human-disturbed areas, it’s often seen in people’s backyards. Around gardens it can be thought of as a helpful neighbour, as it is a keen predator of insects and other invertebrates that may try to eat plants. Yet it also has the potential to be ecologically hazardous outside its native range – and this toad is an accomplished invader.</p>
<p>In the Mascarene Archipelago in the Indian Ocean, far from mainland Africa, these toads have been an established invasive species for almost 100 years. In 1922, the director of dock management in Port Louis, Mauritius, deliberately released guttural toads in an attempt to control <a href="http://www.herpconbio.org/Volume_14/Issue_2/Telford_etal_2019.pdf">cane beetles</a> – a pest of the country’s major crop, sugar cane. This attempt at biocontrol failed, but the toads appeared to thrive and rapidly spread across the island. </p>
<p>Mauritius had no native amphibian species for it to compete with, and no native predators with a recent evolutionary history with toads. In mainland Africa these toads would have to divide resources, like food, with a host of native amphibians and deal with an array of native birds, mammals and snakes that evolved feeding on them. But without these challenges on Mauritius, the toads colonised the entire island rapidly.</p>
<p>Most toads are generalist predators and hunt a wide variety of prey, more or less eating whatever they can fit in their mouth. So as the guttural toad’s population numbers grew through the decades, so too did the concerns from Mauritian ecologists about the impact on native fauna. Anecdotal accounts as early as the 1930s suggest that the toads were having a negative impact on endemic invertebrate populations. In fact it has been suggested that the toads may have been a driver in the decline, and possible extinction, of endemic <a href="https://doi.org/10.1007/s10531-006-9050-9">carabid beetles</a> and <a href="https://islandbiodiversity.com/Phelsuma%2018-2.pdf">snails</a>.</p>
<p>But it’s only recently that the toad’s diet in Mauritius has been examined closely. In our <a href="https://doi.org/10.1111/aje.12814">new study</a> we examined the stomach contents of 361 toads collected in some of the last remaining native forests of Mauritius.</p>
<p>By knowing more about what species the toads are eating, and which groups they favour, our research may help inform toad control actions to protect areas with known sensitive species.</p>
<h2>In the belly of the beast</h2>
<p>Through our research we were able to identify almost 3,000 individual prey items, encompassing a wide variety of invertebrates like insects, woodlice, snails, spiders, millipedes and earthworms.</p>
<p>This research also went one step further to examine the prey preference of the toads. In general, they seemed to favour, some of the more abundant and common prey species. These included ants and woodlice, which made up about two-thirds of their overall diet. </p>
<p>These findings may suggest that the toads were able to identify a readily available food source, and this may have fuelled their invasive population growth. Yet they are also eating prey that represents a more serious conservation concern.</p>
<p>Inside the toads we found 13 different species of native snail, most of which were island endemics. Four species are listed as being vulnerable to extinction and one, <a href="https://doi.org/10.1093/mollus/eym004">Omphalotropis plicosa</a>, being critically endangered – having been presumed extinct until it was rediscovered in 2002. Understandably, we found it very troubling to find a <a href="https://theconversation.com/meet-the-lazarus-creatures-six-species-we-thought-were-extinct-but-arent-50274">“Lazarus species”</a> within the stomach of an invasive predator.</p>
<h2>Unanswered questions</h2>
<p>These early insights into the native species now being hunted by a widespread and voracious predator raise new research questions. To understand the greater impact the toads are having on native species much more work is required to understand their prey’s population dynamics so we can determine if the toad’s invertebrate “harvest” is contributing to declines.</p>
<p>Furthermore, how does the toad’s invasive diet in Mauritius compare with that of other invasive populations, like those in Réunion or Cape Town – is their invasive success linked to a common prey type? And how does it compare with their diet in their own native species range? </p>
<p>Our study could only examine what they are eating currently, but Mauritius has seen numerous species decline over the past 100 years. What role did the toad play in these losses? Perhaps they historically fed more readily on creatures that were more abundant in the past, but had to switch their favour to ants and woodlice when the populations of other species dropped. We may never know.</p>
<p>What is clear is that there is much to learn about the habits of this far-from-home amphibian and its impact on the ecosystems it has invaded.</p><img src="https://counter.theconversation.com/content/149371/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>James Baxter-Gilbert receives funding from DSI-NRF Centre of Excellence for Invasion Biology and is a postdoctoral fellow at Stellenbosch Univeristy. </span></em></p>A new study examines the diet of an invasive population of guttural toads in Mauritius and finds a number of species of conservation concern.James Baxter-Gilbert, Postdoctoral Fellow, Centre for Invasion Biology (C·I·B), Department of Botany & Zoology, Stellenbosch UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1374742020-06-12T12:12:14Z2020-06-12T12:12:14ZMore people eat frog legs than you might think – and humans are harvesting frogs at unsustainable rates<figure><img src="https://images.theconversation.com/files/334161/original/file-20200511-49573-kq1nag.JPG?ixlib=rb-1.1.0&rect=0%2C552%2C2816%2C1408&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Anatolian water frogs (_Pelophylax spp_) could become locally extinct in parts of Turkey due to over-harvesting as food. </span> <span class="attribution"><span class="source">Kerim Çiçek</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Amphibians such as frogs, toads, newts and salamanders, are <a href="http://dx.doi.org/10.1126/science.1194442">the world’s most threatened group of vertebrates</a>. Of the 6,800 species assessed by the International Union for the Conservation of Nature, <a href="https://www.iucnredlist.org/">41% are classified as threatened</a>. The main threats to their survival are well known and include <a href="https://theconversation.com/some-tropical-frogs-may-be-developing-resistance-to-a-deadly-fungal-disease-but-now-salamanders-are-at-risk-95706">disease</a>, pollution, habitat loss and climate change. </p>
<p>Frogs also face another, less-known threat: Humans <a href="https://doi.org/10.1111/j.1523-1739.2008.01165.x">collect many frog species as food</a>. This trade <a href="https://doi.org/10.1890/090111">spreads disease</a>, destroys their habitats and reduces control of mosquitoes and agricultural pests that frogs eat. But there has been very little research on how it affects frog populations. </p>
<p>In a <a href="https://doi.org/10.1017/S0030605319000176">newly published study</a>, we conducted field research in Turkey, where frog harvesting has taken place for some 40 years, to assess its effect. We found that at current rates, Anatolian water frogs – the main species harvested in Turkey – may become extinct in heavily harvested areas within the next 15 to 30 years. But our research also shows that this harvest could be managed more sustainably, which would benefit both frogs and people in the region.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/QtBD5I5ww_o?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">More than one-third of amphibian species are declining worldwide.</span></figcaption>
</figure>
<h2>Global demand</h2>
<p>Frog legs have long been associated with French gastronomy, but people also eat them in other European countries, the United States and Asia. Most of these frogs are caught in the wild in countries far from where they are consumed, such as southeast Asia and the Middle East. Frog harvesting is regulated to different degrees in different countries, ranging from total ban to unregulated harvest.</p>
<p>The largest importers are the U.S. and the European Union, while the largest exporters are Indonesia and China. According to one estimate, <a href="https://doi.org/10.1890/090111">100 million to 400 million frogs</a> are shipped internationally as food each year. </p>
<p>This trade has affected frog populations in many countries. For example, when France and Romania banned commercial frog hunting, <a href="https://www.independent.co.uk/news/world/europe/water-frogs-extinct-decline-turkey-a9510751.html">exports from India and Bangladesh increased</a> in what has been called an “extinction domino effect.” And when those countries adopted their own bans, Indonesia and China became suppliers.</p>
<p>For this study, members of our research team caught and marked almost 14,000 frogs in the Çukurova Region in southern Turkey, a flat, fertile zone that stretches along the Mediterranean Sea. Over three years, we sampled four times per season, tagging and releasing frogs that we found in ponds, canals and streams and then noting when we recaptured them later. </p>
<p>We also observed how people harvest frogs. Harvesters typically work at night in groups of three or four. In one night, a harvester typically captures 45-85 pounds (20-39 kilograms) of frogs, but some manage to collect up to 130 pounds (60 kilograms) – about 3,000 frogs. They sell the frogs to processing plants for about US$1.30 to $5.50 per pound ($0.60 to $2.60 per kilogram), depending on demand.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/334163/original/file-20200511-49542-13j87mb.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/334163/original/file-20200511-49542-13j87mb.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334163/original/file-20200511-49542-13j87mb.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334163/original/file-20200511-49542-13j87mb.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334163/original/file-20200511-49542-13j87mb.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334163/original/file-20200511-49542-13j87mb.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334163/original/file-20200511-49542-13j87mb.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">A harvester collecting frogs in southern Turkey.</span>
<span class="attribution"><span class="source">Kerim Çiçek</span></span>
</figcaption>
</figure>
<p>Anatolian waterfrogs (<em>Pelophylax</em> spp) <a href="https://doi.org/10.1111/j.1365-2699.2010.02368.x">form a species complex</a> made up of two to five closely related species. Frog exporters use uncertainty about how to classify these species to their advantage by labeling all frogs as “edible frog” when they are marketed in Europe, even though the actual species known as Edible Frog (<em>Pelophylax esculentus</em>) does not live in Turkey. </p>
<p>Most consumers are not aware that they are not eating what they have come to know as “Edible Frogs,” much less where their frog legs come from, or what impact their consumption could have on natural populations. </p>
<h2>Frogs under pressure</h2>
<p>We used the data we collected in a population model – a mathematical representation of how a frog population changes over time. Scientists use models like this to study animal and plant populations and forecast their future sizes. <a href="https://scholar.google.com/citations?user=RMg7RqkAAAAJ&hl=en">One of us</a> has developed such mathematical models and applied them to a wide variety of species. They require a lot of data, which is one reason why there have been few studies analyzing the effects of harvest on frog populations.</p>
<p>We found that the frog populations we studied were declining rapidly, by about 20% per year. According to our models, there is a 90% chance that these frog populations may go extinct in the Çukurova Region by 2050 if harvesting trends continue. </p>
<p>However, not all populations of Anatolian waterfrogs are harvested. If enough frogs move between different regions, there is a chance that they could recolonize areas that undergo local extinctions. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/334165/original/file-20200511-49573-1fsdsx0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/334165/original/file-20200511-49573-1fsdsx0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334165/original/file-20200511-49573-1fsdsx0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334165/original/file-20200511-49573-1fsdsx0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334165/original/file-20200511-49573-1fsdsx0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334165/original/file-20200511-49573-1fsdsx0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334165/original/file-20200511-49573-1fsdsx0.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">Harvested frogs processed for export in Turkey.</span>
<span class="attribution"><span class="source">C. Can Bilgin</span></span>
</figcaption>
</figure>
<h2>Protecting frogs and ensuring livelihoods</h2>
<p>Frog harvesting in Turkey is worth nearly $4 million yearly. Our calculations show that Turkey exports more than 36 million frogs annually, about half of them from the Çukurova region. Frog harvesting is the main livelihood for many people in this region. Most harvesters have low incomes, no permanent job and no social benefits. </p>
<p>A ban on frog harvesting would cause this vital source of income to disappear. But so would extinction of these local frog populations. </p>
<p>The good news is that it’s possible to harvest these populations at a sustainable rate. Doing so would increase the total harvest and help the local economy. Our analysis shows that the total number of frogs that can be harvested from these populations in the long term is highest at a moderate harvest rate of about 5% to 10% of the population per year. When this proportion increases to 20% and above, the risk of a population crash increases sharply, and the total amount that can be harvested declines.</p>
<p>Reducing the harvest rate would ensure both the frogs’ survival and local livelihoods. First steps could include a ban on harvesting frogs during the mating season and effective enforcement of size limits that allow only larger frogs to be harvested. Such restrictions are commonly used for other types of wild-caught food, such as <a href="https://www.fisheries.noaa.gov/new-england-mid-atlantic/recreational-fishing/recreational-fishing-regulations-species">marine fish</a>, and there is plenty of evidence suggesting that they can be effective. </p>
<p>As part of our research, we have made relevant government agencies aware of this issue, and hope that the measures we recommend will be implemented soon. With frogs <a href="http://dx.doi.org/10.1126/science.aav0379">declining worldwide</a>, reducing threats from harvest would make an important contribution to the survival of these populations.</p>
<p>[<em>Insight, in your inbox each day.</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=insight">You can get it with The Conversation’s email newsletter</a>.]</p><img src="https://counter.theconversation.com/content/137474/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kerim Cicek receives funding from TUBITAK (The Scientific and Technological Research Council of
Turkey) and EBILTEM (Ege University Science and Technology Centre).</span></em></p><p class="fine-print"><em><span>C. Can Bilgin and H. Resit Akcakaya 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>Frogs are harvested as food by the millions every year. A new study shows that uncontrolled frog hunting could drive some populations to extinction by midcentury.H. Resit Akcakaya, Professor of Ecology and Evolution, Stony Brook University (The State University of New York)C. Can Bilgin, Professor of Biology, Middle East Technical UniversityKerim Çiçek, Associate Professor of Zoology, Ege UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1247102019-10-22T15:01:31Z2019-10-22T15:01:31ZGlobal pet trade in amphibians is bigger than we thought<figure><img src="https://images.theconversation.com/files/297877/original/file-20191021-56198-ebhnfi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Many frogs, such as the red-eyed tree frog, are sought-after pets.</span> <span class="attribution"><span class="source">Andy Morffew/Wikimedia Commons</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Humans keep all sorts of animals as pets and new species are constantly being brought into the trade – some reared in captivity, <a href="https://academic.oup.com/bioscience/article/55/3/256/249719">but many sourced from the wild</a>. As a result, the global pet trade often puts wild populations at risk of over-exploitation. The <a href="https://www.globalwildlife.org/project/global-amphibian-assessment/">Global Amphibian Assessment</a> pegs 47 amphibian species to be predominantly threatened by unsustainable harvesting for the international pet trade. </p>
<p>And the risks don’t end there. For various reasons, people release pets into the wild, <a href="https://doi.org/10.1002/fee.2059">resulting in biological invasions</a>. People might do this because keeping the animal isn’t the experience they expected, or because they can’t afford it any longer. The problem is that, often, it may introduce a species to regions beyond their natural range. These invasive populations can harm native species and lead to the spread of diseases to new areas. For example, the pet trade is linked to the spread of an infectious <a href="https://science.sciencemag.org/content/346/6209/630">fungal disease of salamanders</a> in Europe, leading to large scale salamander mortality.</p>
<p>These threats are especially true for amphibians (frogs, newts and caecilians). Amphibians are undergoing severe population declines all over the world due to habitat destruction, climate change, disease spread, and invasive species. Losing amphibians, pest-controllers par excellence, not only imperils agricultural security but can lead to imbalances in ecosystem processes.</p>
<p>Internet-based commerce is making it easier for the pet trade to include <a href="https://www.academia.edu/25543513/A_review_of_the_international_trade_in_amphibians_the_types_levels_and_dynamics_of_trade_in_CITES-listed_species">growing numbers and new species of amphibians</a>. The trade is now the major pathway through which invasions of amphibians take place. At least 104 amphibian species are invasive around the world, and more species are likely to be introduced in the future.</p>
<p>It is crucial to understand which species may be affected by the trade and which species may spur invasive populations following release. <a href="https://link.springer.com/article/10.1007/s10531-019-01857-x">In our new study</a>, we aimed to assess the amphibian pet trade. We identified which species are being traded and why, and predicted which species are likely to be targeted in future. We uncovered nearly 450 species of amphibians in the pet trade, moved around the world in large numbers. </p>
<p>The US alone imported 3.6 million pet amphibians in the past five years. The magnitude of this trade indicates that more species are likely to be released and become invasive in non-native regions and facilitate disease spread. Amphibian enthusiasts must carefully evaluate whether the species meets their expectations, and understand the cost of ownership, before purchasing.</p>
<h2>Which species are traded?</h2>
<p>We searched the scientific literature and import databases for traded amphibians around the globe. Then we looked at how traded and non-traded species differ from each other. To do this, we used a set of amphibian traits from the database <a href="https://www.nature.com/articles/sdata2017123">AmphiBIO</a>, which contains information on traits such as body size and reproductive capacity. We also looked at whether the species were endangered or not, according to the <a href="https://www.iucnredlist.org/">International Union for Conservation of Nature</a>. We examined whether these traits could explain the size of the trade in each species. </p>
<p>Our effort resulted in a <a href="https://link.springer.com/article/10.1007/s10531-019-01857-x">long list</a> of 443 traded species. We found a strong bias for certain types of amphibians; six amphibian families contributed disproportionately high numbers of traded species. The colourful poison dart frog family is, unsurprisingly, a star attraction in the trade. More surprising as popular pets are the families of tongue-less frogs and reed frogs. </p>
<p>Next, we found that the traded species tend to be bigger. It is likely that extremely small body sizes are avoided because it’s harder for the owner to see or handle the pet often. Traded species also had larger range sizes, probably due to the ease of collecting them from the wild. A final characteristic of traded species was a “larval” breeding type (indirect development), which produces offspring that are cheaper to raise than direct developing species.</p>
<p>These results help explain which species end up in the trade. It’s not just about what pet enthusiasts prefer; it’s also about how easy a species is to collect and to rear in captivity. </p>
<p>Body size, range size and breeding type explained, for the most part, why species are traded. We then used these traits to predict <a href="https://link.springer.com/article/10.1007/s10531-019-01857-x">a list of species</a> that could be future pets. Interestingly, species-traits could not explain the size of trade.</p>
<h2>Blind spots</h2>
<p>Although our investigation provides a good view of the trade, it has some blind spots. Trade in Asia remains understudied and is probably not well reflected in our compiled pet list. We also couldn’t incorporate all the potential factors that may predict popular pets, such as colour and calls, because these traits haven’t been scored for the majority of around 7,000 amphibians we are dealing with in the analysis. But more work is being done by our research lab to understand <a href="https://www.frontiersin.org/articles/10.3389/fevo.2019.00052/full">which traits attract owners of amphibians</a>, which species are likely to be released, and how responsible pet ownership can be promoted. </p>
<p>Pet ownership comes with responsibilities, not just for the well-being of the pets, but for the unwanted effects their trade could have. We hope the information we have gathered will make pet owners and traders more aware of these aspects. With great pets come great responsibilities.</p><img src="https://counter.theconversation.com/content/124710/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dr. Nitya Mohanty receives funding from the DST-NRF Center of Excellence for Invasion Biology. </span></em></p>People sometimes release pets into the wild, resulting in biological invasions.Nitya Mohanty, Post-doctoral fellow Centre for Invasion Biology (C·I·B) Department of Botany & Zoology, Stellenbosch UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1178422019-06-03T20:10:26Z2019-06-03T20:10:26ZA deadly fungus threatens to wipe out 100 frog species – here’s how it can be stopped<p>What would the world be like without frogs? Earth is in its <a href="https://science.sciencemag.org/content/360/6393/1080.2.abstract">sixth mass extinction event</a> and amphibians are among the hardest hit. </p>
<p>But in the island of New Guinea, home to 6% of the world’s frog species, there’s a rare opportunity to save them from the potential conservation disaster of a chytrid fungus outbreak.</p>
<p>The amphibian chytrid fungus is a microscopic, aquatic fungus that infects a protein in frog skin. It interferes with the balance of electrolytes and, in turn, effectively gives frogs a heart attack. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/tiny-frogs-face-a-troubled-future-in-new-guineas-tropical-mountains-75210">Tiny frogs face a troubled future in New Guinea's tropical mountains</a>
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</em>
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<p>If the amphibian chytrid fungus invades New Guinea, we estimate 100 species of frogs could decline or become extinct. This disease, which emerged in the 1980s, has already wiped out <a href="https://science.sciencemag.org/content/363/6434/1459.abstract">90 species of frogs</a> around the world.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/277544/original/file-20190603-69079-1gj1ssk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/277544/original/file-20190603-69079-1gj1ssk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/277544/original/file-20190603-69079-1gj1ssk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/277544/original/file-20190603-69079-1gj1ssk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/277544/original/file-20190603-69079-1gj1ssk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/277544/original/file-20190603-69079-1gj1ssk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/277544/original/file-20190603-69079-1gj1ssk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/277544/original/file-20190603-69079-1gj1ssk.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">The New Guinean horned land frog, <em>Sphenophryne cornuta</em>, with young. These frogs are under threat from a fungus that has wiped out 90 frog species around the world.</span>
<span class="attribution"><span class="source">Stephen Richards</span></span>
</figcaption>
</figure>
<p>Collaborating with 30 international scientists, we <a href="https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1002/fee.2057">developed a way</a> to save New Guinea’s frog species from a mass extinction, one that’s predictable and preventable. We need urgent, unified, international action to prepare for the arrival of the deadly fungus, to slow its spread after it arrives and to limit its impact on the island. </p>
<p>It’s rare we can identify a conservation disaster before it occurs, but a long history of amphibian declines in Australia and South America has equipped us with the <a href="https://frontiersinzoology.biomedcentral.com/articles/10.1186/1742-9994-8-8">knowledge</a> to protect areas where the amphibian chytrid fungus is yet to reach.</p>
<h2>Why we should care about frogs</h2>
<p>Like Australian frogs, New Guinea frogs may be particularly vulnerable to the chytrid fungus. These frogs share a close genetic relationship suggesting that, if exposed, New Guinea frogs may respond similarly to Australian ones, where around 16% of frog species are affected. </p>
<p>Impacted frogs include <a href="https://theconversation.com/australian-endangered-species-southern-corroboree-frog-16189">corroboree frogs</a>, <a href="https://www.iucnredlist.org/species/14969/4484777">Australian lacelid frogs</a> and <a href="https://www.iucnredlist.org/species/12143/3325402">green and golden bell frogs</a>.</p>
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Read more:
<a href="https://theconversation.com/australian-endangered-species-southern-corroboree-frog-16189">Australian endangered species: Southern Corroboree Frog</a>
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<p>Losing so many species can have many terrible impacts. Tadpoles and frogs are important because they help recycle nutrients and break down leaf litter. They are also prey for larger mammals and reptiles, and predators of insects, invertebrates and small vertebrates. They help keep insect plagues, such as those from flies and mosquitoes, in check. </p>
<p>Frogs are also an important source of human medical advancements – they were even used for a <a href="https://www.smithsonianmag.com/smart-news/doctors-used-to-use-live-african-frogs-as-pregnancy-tests-64279275/">human pregnancy test until the 1950s</a>.</p>
<h2>A call to action to protect frogs</h2>
<p>Frogs are one of the most threatened groups of species in the world – <a href="https://www.iucnredlist.org/species/12143/3325402">around 40% are threatened with extinction</a>.</p>
<p>And species conservation is more expensive once the species are threatened. They can be more costly to collect and more precious to maintain, with a greater need for wider input from recovery groups to achieve rapid results.</p>
<p>In our study, we highlight the increased costs and requirements for establishing captive breeding for two species of closely related barred frog, one common and one threatened. We determined that waiting until a species is threatened dramatically increases the costs and effort required to establish a successful breeding program. The risks of it failing also increase. </p>
<p>Our research draws on lessons learned from other emerging diseases and approaches taken in other countries. By addressing the criteria of preparedness, prevention, detection, response and recovery, we detail a call for action to protect the frogs of New Guinea. It will require dedicated funding, a contingency plan for the likely, eventual arrival of the disease and a task force to oversee it. </p>
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Read more:
<a href="https://theconversation.com/frogs-v-fungus-time-is-running-out-to-save-seven-unique-species-from-disease-57432">Frogs v fungus: time is running out to save seven unique species from disease</a>
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<p>This task force would oversee active monitoring for disease and prepare an action plan to implement on the disease’s arrival. We have already begun to establish facilities that can handle captive breeding and gene banking for frogs in collaboration with PNG counterparts.</p>
<p>The need for <a href="https://science.sciencemag.org/content/357/6350/454.summary">amphibian conservation in New Guinea</a> also presents an opportunity for investment and training of local scientists. More species unknown to science will be described and the secret habits of these unique frogs will be discovered before they are potentially lost.</p>
<h2>Conservation in New Guinea is complicated</h2>
<p>The island of New Guinea is governed by Papua New Guinea on the eastern side and Indonesia on the western side. So it will take a coordinated approach to reduce risks in both countries for successful biosecurity.</p>
<p>Historically, New Guinea has had little import or <a href="https://www.ifc.org/wps/wcm/connect/news_ext_content/ifc_external_corporate_site/news+and+events/news/attracting+tourists+to+papua+new+guinea">tourism</a>. But as the <a href="http://www.agriculture.gov.au/about/media-centre/media-releases/working-png-strengthen-aus-biosecurity">country develops</a>, it becomes more at risk of emerging diseases through increased trade and and entry of tourists from chytrid-infected regions, especially with little biosecurity at entry ports. </p>
<p>What’s more, many species there are unknown to science and few ecological studies have documented their habitat requirements. Unlike Australia, many of New Guinea’s frogs have adapted for life in the wet rainforest. </p>
<p>Rather than developing into tadpoles that live in water, more than 200 frog species in New Guinea hatch from their eggs as fully formed baby frogs. It’s difficult for us to predict how the amphibian chytrid fungus will affect these frogs because Australia has only a handful of these types of species. </p>
<p>We don’t know how to remove the amphibian chytrid fungus from large areas once it has invaded, so strict biosecurity and conservation contingency planning is needed to protect New Guinea’s frogs. </p>
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Read more:
<a href="https://theconversation.com/friday-essay-frogwatching-charting-climate-changes-impact-in-the-here-and-now-98161">Friday essay: frogwatching – charting climate change's impact in the here and now</a>
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<p>For example, all incoming goods into New Guinea should be inspected for possible hitchhiker frogs that could carry chytrid. Camping or hiking equipment carried by tourists should also be closely inspected for attached mud, which could harbour the pathogen, as is the case in Australia.</p>
<p>International researchers have experience in emerging amphibian diseases. Papua New Guineans and Indonesians have traditional and ecological expertise. Together we have the opportunity to avert another mass decline of frogs. Without taking action, we could lose a hundred more species from the world and take another step towards mass extinction.</p><img src="https://counter.theconversation.com/content/117842/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Deborah Bower is affiliated with the University of New England.</span></em></p><p class="fine-print"><em><span>Simon Clulow is affiliated with Macquarie University. </span></em></p>The island of New Guinea is home to 6% of the world’s frogs, but if the deadly chytrid fungus invades it could cause a mass extinction.Deborah Bower, Lecturer in Ecosystem Rehabilitation, University of New EnglandSimon Clulow, MQ Research Fellow, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1138462019-03-28T18:10:34Z2019-03-28T18:10:34ZDeadly frog fungus has wiped out 90 species and threatens hundreds more<figure><img src="https://images.theconversation.com/files/266273/original/file-20190328-139341-1bs2rtv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Mossy Red-eyed Frog is among hundreds of species threatened with extinction at the hands of chytrid fungus.</span> <span class="attribution"><span class="source">Jonathan Kolby/Honduras Amphibian Rescue and Conservation Center</span></span></figcaption></figure><p>It started off as an enigma. Biologists at field sites around the world reported that frogs had simply disappeared. Costa Rica, 1987: the golden toad, missing. Australia, 1979: the <a href="http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=1909">gastric brooding frog</a>, gone. In Ecuador, Arthur’s stubfoot toad was last seen in 1988.</p>
<p>By 1990, cases of unexplained frog declines were piling up. These were not isolated incidents; it was a global pattern – one that we now know was due to chytridiomycosis, a fungal disease that was infecting and killing a huge range of frogs, toads and salamanders. </p>
<p>Our research, <a href="http://science.sciencemag.org/cgi/doi/10.1126/science.aav0379">published today in Science</a>, reveals the global number of amphibian species affected. At least 501 species have declined due to chytrid, and 90 of them are confirmed or believed extinct.</p>
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Read more:
<a href="https://theconversation.com/where-did-the-frog-pandemic-come-from-14259">Where did the frog pandemic come from?</a>
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<p>When biologists first began to investigate the mysterious species disappearances, they were at a loss to explain them. In many cases, species declined rapidly in seemingly pristine habitat.</p>
<p>Species declines typically have obvious causes, such as habitat loss or introduced species like rats. But this was different.</p>
<p>The first big breakthrough came in 1998, when a team of Australian and international scientists led by Lee Berger <a href="https://www.pnas.org/content/95/15/9031.short">discovered amphibian chytrid fungus</a>. Their research showed that this unusual fungal pathogen was the cause of frog declines in the rainforests of Australia and Central America.</p>
<p>However, there were still many unknowns. Where did this pathogen come from? How does it kill frogs? And why were so many different species affected?</p>
<p>After years of painstaking research, biologists have filled in many pieces of the puzzle. In 2009, researchers discovered <a href="http://science.sciencemag.org/content/326/5952/582">how chytrid fungus kills frogs</a>. In 2018, the Korean peninsula was pinpointed as the <a href="http://science.sciencemag.org/content/360/6389/621">likely origin</a> of the most deadly lineage of chytrid fungus, and human dispersal of amphibians suggested as a likely source of the global spread of the pathogen.</p>
<p>Yet as the mystery was slowly but surely unravelled, a key question remained: how many amphibian species have been affected by chytrid fungus? </p>
<p><a href="https://link.springer.com/article/10.1007/s10393-007-0093-5">Early estimates</a> suggested that about 200 species were affected. Our new study reveals the total is unfortunately much larger: 501 species have declined, and 90 confirmed or suspected to have been killed off altogether.</p>
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<a href="https://images.theconversation.com/files/266281/original/file-20190328-139371-1nbfup0.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/266281/original/file-20190328-139371-1nbfup0.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/266281/original/file-20190328-139371-1nbfup0.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/266281/original/file-20190328-139371-1nbfup0.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/266281/original/file-20190328-139371-1nbfup0.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/266281/original/file-20190328-139371-1nbfup0.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/266281/original/file-20190328-139371-1nbfup0.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/266281/original/file-20190328-139371-1nbfup0.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"></a>
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<span class="caption">The toll taken by chytrid fungus on amphibians around the world. Each bar represents one species; colours reveal the extent of population declines.</span>
<span class="attribution"><span class="source">Scheele et al. Science 2019</span></span>
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<h2>Devastating killer</h2>
<p>These numbers put chytrid fungus in the worst league of invasive species worldwide, threatening similar numbers of species as <a href="https://www.pnas.org/content/113/40/11261">rats and cats</a>. The worst-hit areas have been in Australia and Central and South America, which have many different frog species, as well as ideal conditions for the growth of chytrid fungus. </p>
<p>Large species and those with small distributions and elevational ranges have been the mostly likely to experience severe declines or extinctions.</p>
<p>Together with 41 amphibian experts from around the world, we pieced together information on the timing of species declines using published records, survey data, and museum collections. We found that declines peaked globally in the 1980s, about 15 years before the disease was even discovered. This peak coincides with biologists’ anecdotal reports of unusual amphibian declines that occurred with increasing frequency in the late 1980s.</p>
<p>Encouragingly, some species have shown signs of natural recovery. Twelve per cent of the 501 species have begun to recover in some locations. But for the vast majority of species, population numbers are still far below what they once were.</p>
<p>Most of the afflicted species have not yet begun to bounce back, and many continue to decline. Rapid and substantial action from governments and conservation organisations is needed if we are to keep these species off the extinct list.</p>
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Read more:
<a href="https://theconversation.com/saving-amphibians-from-a-deadly-fungus-means-acting-without-knowing-all-the-answers-81739">Saving amphibians from a deadly fungus means acting without knowing all the answers</a>
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<p>In Australia, chytrid fungus has caused the decline of 43 frog species. Of these, seven are now extinct and six are at high risk of extinction due to severe and ongoing declines. The conservation of these species is dependent on targeted management, such as the recovery program for the iconic <a href="https://theconversation.com/australian-endangered-species-southern-corroboree-frog-16189">corroboree frogs</a>.</p>
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<a href="https://images.theconversation.com/files/266282/original/file-20190328-139345-16omz5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/266282/original/file-20190328-139345-16omz5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/266282/original/file-20190328-139345-16omz5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/266282/original/file-20190328-139345-16omz5g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/266282/original/file-20190328-139345-16omz5g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/266282/original/file-20190328-139345-16omz5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/266282/original/file-20190328-139345-16omz5g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/266282/original/file-20190328-139345-16omz5g.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>
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<span class="caption">The southern corroboree frog: hopefully not a disappearing icon.</span>
<span class="attribution"><span class="source">Corey Doughty</span></span>
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<p>Importantly, there are still some areas of the world that chytrid has not yet reached, such as New Guinea. Stopping chytrid fungus spreading to these areas will require a dramatic reduction in the global trade of amphibians, as well as increased biosecurity measures.</p>
<p>The unprecedented deadliness of a single disease affecting an entire class of animals highlights the need for governments and international organisations to take the threat of wildlife disease seriously. Losing more amazing species like the golden toad and gastric brooding frog is a tragedy that we can avoid.</p><img src="https://counter.theconversation.com/content/113846/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Benjamin Scheele receives funding from the Threatened Species Recovery Hub of the Australian Government’s National Environmental Science Program</span></em></p><p class="fine-print"><em><span>Claire Foster receives funding from the Australian Research Council and the Australian Government</span></em></p>Chytrid fungus has caused declines in 501 amphibian species, according to a new analysis. Most of the damage happened in the 1980s, before the fungus itself was even discovered.Benjamin Scheele, Research Fellow in Ecology, Australian National UniversityClaire Foster, Research Fellow in Ecology and Conservation, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1090572018-12-19T15:42:57Z2018-12-19T15:42:57ZThe animal world is still awesome: 3 essential reads<figure><img src="https://images.theconversation.com/files/251356/original/file-20181218-27752-b81gpp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Some tropical frogs may be developing resistance to a fungus that has devastated species like _Atelopus varius_, the variable harlequin frog.</span> <span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Atelopus_varius#/media/File:Atelopus_varius_1.jpg">Brian Gratwicke/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p><em>Editor’s note: As we come to the end of the year, Conversation editors take a look back at the stories that – for them – exemplified 2018.</em> </p>
<p>As the effects of climate change become more apparent and widespread, it’s easy to feel that our species is the biggest threat to life on Earth. Indeed, one recent study warned that extreme environmental change could cause an “<a href="http://dx.doi.org/10.1038/s41598-018-35068-1">extinction domino effect</a>,” in which one species dies out, then another species that depends on it, and so on. </p>
<p>When headlines like this seem overwhelming, I remind myself that scholars are still learning about all kinds of amazing life forms. Here are three 2018 stories that remind us how awesome the animal world is.</p>
<h2>1. Madagascar’s ultra-elusive fossa</h2>
<p>If Americans have even heard of fossa (<em>Cryptoprocta ferox</em>), a catlike carnivore found only on Madagascar, it’s usually from the animated <em>Madagascar</em> movies. Fossa are the island’s real-life apex predator, but are so rare and hard to track that scientists know very little about them – even how many there are. </p>
<p>Penn State University doctoral candidate <a href="https://scholar.google.com/citations?user=1sKwZagAAAAJ&hl=en">Asia Murphy</a> was part of a seven-year project that <a href="https://theconversation.com/caught-on-camera-the-fossa-madagascars-elusive-top-predator-99172">documented fossa numbers with camera traps</a>. By focusing on features like scars, ear nicks, and tail width and kinkiness, scientists could pick out certain fossa from the population and “follow” them from one camera to another. Their survey data and population density estimates will support habitat protection efforts. </p>
<p>“In all of this time, I never personally saw a fossa, but two local field assistants saw fossa in the trees once or twice,” Murphy writes. She’d like to see these animals get more attention from the conservation world, and suggests that it’s time for #FossaFriday.</p>
<h2>2. Forests at the bottom of the sea</h2>
<p>Scientists go to many extremes to find life forms. In August, a research expedition off the coast of South Carolina found a huge series of coldwater coral “forests,” covering about 85 miles, in water more than three miles deep. </p>
<p>Coldwater corals “are <a href="https://theconversation.com/deepwater-corals-thrive-at-the-bottom-of-the-ocean-but-cant-escape-human-impacts-104211">just as ecologically important as their shallow water counterparts</a>,” writes Florida State University research scientist <a href="https://www.marinelab.fsu.edu/people/faculty/sandra-brooke">Sandra Brooke</a>, who was on the cruise and went down in the <a href="http://www.whoi.edu/main/hov-alvin">Alvin submersible</a> to see coral formations on the ocean floor. </p>
<p>Unlike shallow-water corals, which get much of their energy from sunlight, deepwater corals feed on organic material and zooplankton that drift to them on ocean currents. They grow extremely slowly: One black coral is estimated to be more than 4,200 years old. Industrial fishing, offshore drilling and seabed mining could damage deepsea reefs before they’re even mapped – all the more reason, Brooke asserts, to get out and find them now.</p>
<h2>3. Fending off frog plague?</h2>
<p>In recent years a chytrid pathogen abbreviated as Bd has caused mass dieoffs of frog populations around the world. But in a study published in March 2018, Vanderbilt University biologist <a href="https://as.vanderbilt.edu/biosci/bio/louise-rollins-smith">Louise Rollins-Smith</a> and others reported that some tropical frogs in Panama appeared to be <a href="https://theconversation.com/some-tropical-frogs-may-be-developing-resistance-to-a-deadly-fungal-disease-but-now-salamanders-are-at-risk-95706">developing improved skin defenses</a> against Bd – big news for amphibian researchers. </p>
<p>“Many amphibians have granular glands in their skin that synthesize and sequester antimicrobial peptides and other defensive molecules,” Rollins-Smith explains. “When the animal is alarmed or injured, the defensive molecules are released to cleanse and protect the skin.” Scientists don’t know how, but these defenses seemed to improve after Bd entered some frog communities. </p>
<p>Alarmingly, a second chytrid fungus, abbreviated as Bsal, has emerged in Europe and is thought to seriously threaten salamanders. Scholars are urging the U.S. government to suspend all imports of frogs and salamanders until this new threat is better understood. Yet more reason to keep learning about wild species, seen and unseen, all around us.</p><img src="https://counter.theconversation.com/content/109057/count.gif" alt="The Conversation" width="1" height="1" />
A look at new research published in 2018 on fossa, deepsea corals and tropical frogs developing resistance to a deadly fungus.Jennifer Weeks, Senior Environment + Cities Editor, The ConversationLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1033622018-09-19T20:13:25Z2018-09-19T20:13:25ZWe’ve cracked the cane toad genome, and that could help put the brakes on its invasion<figure><img src="https://images.theconversation.com/files/237014/original/file-20180919-143281-y2z5wl.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cane toads are on the march, but new genetic research could slow them down.</span> <span class="attribution"><span class="source">Michael Linnenbach</span></span></figcaption></figure><p>We and our international colleagues have deciphered the genetic code of the cane toad. The complete sequence, <a href="https://academic.oup.com/gigascience/advance-article/doi/10.1093/gigascience/giy095/5067871">published today in the journal GigaScience</a>, will help us understand how the toad can quickly evolve to adapt to new environments, how its infamous toxin works, and hopefully give us new options for halting this invader’s march across Australia.</p>
<p>Since its introduction into Queensland in 1935, the cane toad has spread widely and now occupies <a href="http://rspb.royalsocietypublishing.org/content/274/1616/1413">more than 1.2 million square kilometres of Australia</a>. It is fatally poisonous to predators such as the northern quoll, freshwater crocodiles, and several species of native lizards and snakes.</p>
<p>Previous attempts to sequence the cane toad, by WA researchers more than 10 years ago, were <a href="http://www.news.uwa.edu.au/oct-2007/new-research-funding-awarded-help-find-cane-toad-achilles-heel">not successful</a>, largely because the existing technology could not assemble the genetic pieces to create a genome. But thanks to new methods, we have succeeded in piecing together the entire genetic sequence.</p>
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Read more:
<a href="https://theconversation.com/yes-you-heard-right-more-cane-toads-really-can-help-us-fight-cane-toads-67241">Yes, you heard right: more cane toads really can help us fight cane toads</a>
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<p>Our team, which also featured researchers from Portugal and Brazil, worked at the <a href="https://www.ramaciotti.unsw.edu.au/">Ramaciotti Centre for Genomics</a> at UNSW. This centre played a key role in decoding the genomes of other iconic Australian species, including the koala.</p>
<p>Sequencing, assembling and annotating a genome (working out which genes go where) is a complicated process. The cane toad genome is similar in size to that of humans, at roughly 3 billion DNA “letters”. By using cutting-edge technology, our team sequenced more than 360 billion letters of cane toad DNA code, and then assembled these overlapping pieces to produce one of the best-quality amphibian genomes to date.</p>
<p>We deduced more than 90% of the cane toad’s genes using technology that can sequence very long pieces of DNA. This made the task of putting together the genome jigsaw much easier.</p>
<h2>Toxic toads</h2>
<p>The cane toad has iconic status in Australia, with many Aussies loving to hate the poisonous invasive amphibian. This is a little unfair. It’s not the cane toad’s fault – it was humans who chose to bring it to Australia. </p>
<p>Our obsession with sugar in the 1800s led to the toad’s introduction to many countries around the world. Wherever sugar cane was planted, the cane toad followed, taken from plantation to plantation by landowners as the warty interlopers travelled from South America to the Caribbean and then on to Hawaii and Australia. </p>
<p>But unlike most other places to which the cane toad was introduced, Australia lacks any native toads of its own. The cane toad’s powerful poisons are deadly to native species that have never before encountered this amphibian’s arsenal.</p>
<p>The cane toad has therefore been subject to detailed evolutionary and ecological research in Australia, revealing not only its impact but also its amazing capacity for rapid evolution. Within 83 years of its introduction, cane toads in Australia have evolved a wide range of modifications that affect their body shape, physiology and behaviour. </p>
<p>For example, cane toads at the invasion front are longer-legged and bolder than those in long-colonised areas and invest less into their immune defences (for a summary, see <a href="https://www.ucpress.edu/book/9780520295100/cane-toad-wars">Cane Toad Wars</a> by Rick Shine). </p>
<p>The new genome will give us insights into how evolution transformed a sedentary amphibian into a formidable invasion machine. And it could give us new weapons to help stop, or at least slow, this invasion.</p>
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<h2>Viral control</h2>
<p>Current measures such as physical removal have not been successful in preventing cane toads from spreading, so fresh approaches are needed. One option may be to use a virus to help control the toad population. </p>
<p>Viruses such as myxomatosis have been <a href="https://theconversation.com/tandem-virus-cocktail-kills-pest-rabbits-more-effectively-97930">successfully used to control rabbits</a>. But the cane toad viruses <a href="https://doi.org/10.1111/j.1469-1795.2009.00319.x">studied so far</a> are also infectious to native frogs. The new genome could potentially help scientists hunt for viruses that attack only toads. </p>
<p>In a <a href="https://jvi.asm.org/content/early/2018/06/07/JVI.00768-18">study published this month</a>, we and other colleagues describe how we sampled genetic sequences from cane toads from different Australian locations, and found three viruses that are genetically similar to viruses that infect frogs, reptiles and fish. These viruses could potentially be used as biocontrol agents, although only after comprehensive testing to check that they pose no danger to any other native species.</p>
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Read more:
<a href="https://theconversation.com/come-hither-how-imitating-mating-males-could-cut-cane-toad-numbers-93484">Come hither... how imitating mating males could cut cane toad numbers</a>
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<p>The full cane toad genome will help to accelerate this kind of research, as well as research on the toads’ evolution and its interactions with the wider ecosystem. The published sequence is freely available for anyone to use in their studies. It is one of very few amphibian genomes sequenced so far, so this is also great news for amphibian biologists in general. </p>
<p>As the cane toads continue their march across the Australian landscape, this milestone piece of research should help us put a few more roadblocks in their path.</p><img src="https://counter.theconversation.com/content/103362/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rick Shine receives funding from the Australian Research Council.</span></em></p><p class="fine-print"><em><span>Alice Russo and Peter White 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>New genetic knowledge about cane toads could give us the knowledge we need to throw some more roadblocks in front of this persistent invader as it marches across Australia.Peter White, Professor in Microbiology and Molecular Biology, UNSW SydneyAlice Russo, PhD candidate, UNSW SydneyRick Shine, Professor in Evolutionary Biology, University of SydneyLicensed as Creative Commons – attribution, no derivatives.