tag:theconversation.com,2011:/uk/topics/toads-35437/articlesToads – The Conversation2023-06-06T12:32:21Ztag:theconversation.com,2011:article/2060832023-06-06T12:32:21Z2023-06-06T12:32:21ZChanging wild animals’ behavior could help save them – but is it ethical?<figure><img src="https://images.theconversation.com/files/529493/original/file-20230601-23190-28jc5b.jpg?ixlib=rb-1.1.0&rect=16%2C5%2C3713%2C2477&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cane toads: very large, very invasive and very poisonous.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/cane-toad-rhinella-marina-royalty-free-image/505306855?phrase=%22cane+toad%22&adppopup=true">reptiles4all/iStock via Getty Images Plus</a></span></figcaption></figure><p>When large and warty cane toads were first brought to Australia nearly 100 years ago, they had a simple mission: to gobble up beetles and other pests in the sugarcane fields.</p>
<p>Today, though, the toads have become an infamous example of a global problem: <a href="https://www.dcceew.gov.au/environment/invasive-species/publications/factsheet-cane-toad-bufo-marinus#:%7E:text=Cane%20toads%20became%20pests%20after,continue%20to%20spread%20across%20Australia.">biocontrol initiatives gone wrong</a>. The squat creatures have spread across the top half of the country, wreaking havoc on ecosystems. Cane toads are highly toxic, and consuming just one is generally lethal for predators like monitor lizards, freshwater crocodiles and the small, spotted marsupials called quolls.</p>
<p>But what if you taught other animals not to eat the toads? Could you – and should you?</p>
<p>Conservation behavior scientists <a href="https://www.canetoadcoalition.com/">are doing just that</a>. One of the most exciting areas in this quickly evolving field is behavior-based management, in which an animal’s behavior is encouraged, modified or manipulated in some way to achieve positive conservation outcomes. </p>
<p>In Australia, scientists are working with Indigenous rangers to <a href="https://theconversation.com/how-indigenous-expertise-improves-science-the-curious-case-of-shy-lizards-and-deadly-cane-toads-113997">teach predators not to eat cane toads</a>. Next door in New Zealand – or Aotearoa, in the Indigenous Māori language – researchers, including one of us, <a href="https://scholar.google.com/citations?user=4s3yDa4AAAAJ&hl=en&oi=sra">Catherine Price</a>, <a href="https://theconversation.com/how-we-created-fake-smells-to-trick-predators-and-save-endangered-birds-podcast-165216">have used fake scents</a> to condition ferrets, hedgehogs and other predators to ignore endangered birds’ eggs. Other behavior-based management efforts include re-teaching <a href="https://airandspace.si.edu/stories/editorial/operation-migration#:%7E:text=The%20whooping%20cranes'%20migration%20route,courtesy%20of%20the%20Smithsonian%20Institution.">lost migratory routes</a> to birds in North America, <a href="https://theconversation.com/we-train-colombian-woolly-monkeys-to-be-wild-again-and-maybe-save-them-from-extinction-105022">preparing captive animals for life in the wild</a> in Colombia and using deterrents like colored flags <a href="https://doi.org/10.1002/ecs2.2967">to keep wildlife away</a> from sites where they might conflict with humans.</p>
<p>This research has significant potential to conserve threatened species and reduce animal deaths. However, modifying behavior may come at a cost to animals or the communities they live in.</p>
<p>We are <a href="https://blumsteinlab.eeb.ucla.edu/">scientists</a> and <a href="https://www.sydney.edu.au/arts/about/our-people/academic-staff/thom-van-dooren.html">philosophers</a> who study conservation and the ethical dilemmas involved in modifying animal behavior. Working with colleagues, we have developed a framework to help researchers <a href="https://doi.org/10.1016/j.tree.2023.04.011">evaluate the ethical considerations of conservation behavior</a> interventions against other options.</p>
<h2>Humane solutions</h2>
<p>One important dimension of behavioral interventions is their potential to conserve species and ecosystems without <a href="https://doi.org/10.1038/541148a">shooting, poisoning or trapping animals</a> that people view as problems, which has become standard practice in many parts of the world. This is particularly appealing in cases where the animal is endangered. </p>
<p>Elephants, for example, are often killed by accident or on purpose when they wander into human environments <a href="https://doi.org/10.1080/08941920.2011.638362">like farmers’ fields</a> or railroads. In Kenya, farmers and researchers <a href="https://www.scientificamerican.com/article/living-bee-fences-protect-farmers-from-elephants-and-vice-versa/#">have built “bee fences</a>” that use elephants’ fear of bees to keep them out of crops.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/529494/original/file-20230601-24-5aijho.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A dead elephant lays on its side, with flowers placed nearby, as a woman in a sari kneels nearby." src="https://images.theconversation.com/files/529494/original/file-20230601-24-5aijho.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/529494/original/file-20230601-24-5aijho.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/529494/original/file-20230601-24-5aijho.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/529494/original/file-20230601-24-5aijho.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/529494/original/file-20230601-24-5aijho.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/529494/original/file-20230601-24-5aijho.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/529494/original/file-20230601-24-5aijho.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">A woman pays tribute to a dead elephant that was hit by a train in northeastern India.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/woman-pays-tribute-to-a-dead-elephant-that-was-hit-by-a-news-photo/1236951192?adppopup=true">Str/Xinhua via Getty Images</a></span>
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<p>There are a growing number of other contexts in which it is impractical, publicly unacceptable or just undesirable to kill some animals in order to conserve others, or to achieve other wildlife management goals – like <a href="https://doi.org/10.3354/meps10482">keeping seals away from salmon farms</a> or <a href="https://edmontonurbancoyotes.ca/whatcanido.php">coyotes out of suburbs</a>. Behavioral interventions are increasingly viewed as a more ethical conservation and wildlife management possibility.</p>
<h2>Ethical questions</h2>
<p>While we think there is great potential, behavior-based interventions also <a href="https://doi.org/10.1016/j.tree.2023.04.011">open up new ethical questions</a>, or raise old questions in new ways.</p>
<p>Some concern animal welfare. While avoiding poisoning or shooting animals can reduce overall harm, behavioral management may generate other forms of harm. For example, using aversive stimuli such as loud noises, harassment or mild pain to train species to avoid an area may cause distress and even trauma. In other cases, there are incidental harms to other species, such as animals killed <a href="https://doi.org/10.1111/1749-4877.12226">to be used as “bait</a>” in behavioral interventions.</p>
<p>Changing an animal’s behavior may impact local communities’ livelihoods and cultural practices, too, whether for good or ill – like ranchers and farmers asked <a href="https://bioone.org/journals/wildlife-research/volume-40/issue-3/WR12176/No-trespassing-using-a-biofence-to-manipulate-wolf-movements/10.1071/WR12176.short">to use scent “biofences</a>” to keep predators away from their livestock.</p>
<p>What’s more, some people believe deliberately modifying animal behaviors is unacceptable. To take one iconic example, as California condors neared extinction in the wild, some conservationists pushed for intensive interventions <a href="https://doi.org/10.1093/acprof:oso/9780199977994.003.0013">and captive breeding</a>. Others were so strongly opposed that they viewed extinction as preferable, arguing that the condor was “better dead than bred.”</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/529506/original/file-20230601-23355-bxz3yn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A large hawk-like bird soars over a canyon." src="https://images.theconversation.com/files/529506/original/file-20230601-23355-bxz3yn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/529506/original/file-20230601-23355-bxz3yn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/529506/original/file-20230601-23355-bxz3yn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/529506/original/file-20230601-23355-bxz3yn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/529506/original/file-20230601-23355-bxz3yn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/529506/original/file-20230601-23355-bxz3yn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/529506/original/file-20230601-23355-bxz3yn.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">A California condor tagged No. 19 drifts over the Colorado River, seen from Navajo Bridge near Marble Canyon, Arizona.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/marble-canyon-arizona-july-1-2022-california-condor-drifts-news-photo/1253158097?adppopup=true">Carolyn Cole/Los Angeles Times via Getty Images</a></span>
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<p>Another potentially significant issue is what we have named “behavioral bycatch”: all the costs for organisms unintentionally caught up in a behavior-based management project. For example, some fish farms have tried to prevent seals from eating their fish by using a device that plays an unpleasant sound: <a href="https://hakaimagazine.com/news/looking-for-a-better-way-to-scare-seals/">a seal’s version of “fingernails on a chalkboard</a>.” But in <a href="https://doi.org/10.3354/meps10482">one study</a>, scientists discovered that toothed whales were even more sensitive to the sound and less likely to adjust to it. As a result, these “non-target” animals may be more prone to abandoning the area than the target animals.</p>
<h2>Weighing values</h2>
<p>We argue that in order to make wise decisions, wildlife managers need to <a href="https://doi.org/10.1016/j.tree.2023.04.011">identify the diverse values at stake</a> in a given situation. This might involve cultural and heritage values – such as the significance of hunting in an Indigenous culture – as well as economic and aesthetic values. It will also likely include the welfare of individual animals, the health of ecosystems and perhaps animals’ ability to live with minimal interference.</p>
<p>Together, we developed a framework to help identify and discuss these sometimes conflicting values in any given situation. The value of boosting one endangered species’ breeding success, for example, might need to be considered against the suffering of other individual animals caught up in the intervention process.</p>
<p>We then created a series of steps to support conservation workers as they compare and contrast the ethical dimensions of possible behavior-based management approaches and <a href="https://doi.org/10.1016/j.tree.2023.04.011">decide on the best course of action</a>. It is key for managers to be clear about what a proposed intervention is trying to achieve and how likely it is to meet that goal. Next is weighing the potential effects on a broader range of species, including people: For example, might it enable a sustainable agricultural harvest?</p>
<p>These resources are not intended to provide definitive answers. However, they allow researchers to focus on some of the key potential impacts, then compare these to other methods that might be attempted. Today, virtually all conservation challenges have a human dimension, and it’s important to recognize that the most effective solutions may involve changing people’s behavior, not animals’ – like controlling human food waste to discourage “problem bears.”</p>
<p>Ultimately, we see great value in conservation behavioral interventions, but also some challenges. We hope slowing down to consider the values at stake in conservation behavior interventions will help minimize harm and maximize benefits – to both humans and wildlife.</p><img src="https://counter.theconversation.com/content/206083/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Daniel T. Blumstein receives funding from the National Science Foundation. He is chief editor of Frontiers in Conservation Science.</span></em></p><p class="fine-print"><em><span>Catherine Price receives funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Thom van Dooren receives funding from the Australian Research Council. </span></em></p>Behavior-based interventions could boost conservation efforts, but raise their own set of tricky ethical issues.Daniel T. Blumstein, Professor in the Department of Ecology and Evolutionary Biology and the Institute of the Environment and Sustainability, University of California, Los AngelesCatherine Price, Discovery Early Career Research Fellow, University of SydneyThom van Dooren, Associate Professor and Deputy Director, Sydney Environment Institute, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1885622022-08-22T14:51:34Z2022-08-22T14:51:34ZAncient frogs in mass grave died from too much sex – new research<figure><img src="https://images.theconversation.com/files/480360/original/file-20220822-76732-9t0pw.JPG?ixlib=rb-1.1.0&rect=0%2C26%2C6000%2C3961&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The author looking at fossil specimens from the Geiseltal collection in Germany</span> <span class="attribution"><span class="source">Daniel Falk</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Frogs once lived alongside dinosaurs. It’s incredible to think these little creatures <a href="https://choice.npr.org/index.html?origin=https://www.npr.org/sections/thetwo-way/2017/07/03/535383841/how-frogs-benefited-from-the-dinosaurs-extinction#:%7E:text=But%20scientists%20say%20they've,vacuum%20other%20animals%20left%20behind">survived the dinosaurs’ extinction.</a> But a lower level mass death did take place in what is now called the Geiseltal region in central Germany and the cause has long remained a mystery. </p>
<p>Hundreds of frog <a href="https://www.booklooker.de/B%C3%BCcher/Angebote/titel=Das+eoz%C3%A4ne+Geiseltal">fossils</a> were found in a mass grave in Geiseltal’s 45-million-year-old swampy coastlands, and their reason for being there has confounded scientists for decades. But my team’s <a href="https://doi.org/10.1002/spp2.1453">study</a> found an explanation: they died from exhaustion while mating. </p>
<p>We also found evidence the mating behaviour of modern frogs and toads dates back at least 45 million years as mass grave frog fossils from <a href="https://doi.org/10.2110/palo.2010.p10-126r">other sites</a> show similar features on the skeletons as the Geiseltal specimens. </p>
<h2>What we found</h2>
<p>My Irish-German research team studied the fossil frog skeletons. We palaeontologists took photos, made drawings and analysed the fossils. We checked how many bones were still in place and which bones and joints were still attached. </p>
<p>With this data we were able to reveal what happened to the frog skeletons after their death and to interpret the reason for their death. Our research also found many skeletins in one sediment layer which showed that most of the fossilised frogs died in mass mortality events (recurring events during which many hundreds of frogs died in a short time). </p>
<p>Other scientists thought the Geiseltal frogs and toads died when lakes dried up and oxygen levels <a href="https://onlinelibrary.wiley.com/doi/10.1002/spp2.1453">decreased rapidly</a>. But our research showed this was unlikely as the frogs could have easily made their way to nearby water bodies. We also found evidence the frog carcasses floated in the water for some time before they sank to the lake bottom. So the lake didn’t dry out. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/479392/original/file-20220816-2693-vyi0qu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/479392/original/file-20220816-2693-vyi0qu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=958&fit=crop&dpr=1 600w, https://images.theconversation.com/files/479392/original/file-20220816-2693-vyi0qu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=958&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/479392/original/file-20220816-2693-vyi0qu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=958&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/479392/original/file-20220816-2693-vyi0qu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1204&fit=crop&dpr=1 754w, https://images.theconversation.com/files/479392/original/file-20220816-2693-vyi0qu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1204&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/479392/original/file-20220816-2693-vyi0qu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1204&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Ancient Geiseltal frog.</span>
<span class="attribution"><span class="source">Daniel Falk</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Our comparisons of Geiseltal skeletons with modern frogs revealed most Geiseltal frogs were actually toads. Toads follow a <a href="https://www.jstor.org/stable/1564675?origin=crossref#metadata_info_tab_contents">land based lifestyle</a>, except when they return to ponds to mate. They mated with numerous other toads during the very short mating season which, in some <a href="https://bmcecol.biomedcentral.com/articles/10.1186/s12898-019-0243-y">modern tropical species</a>, lasts for just hours. </p>
<p>Sex can be a death trap for modern toad and frog species. Individuals are regularly overcome by exhaustion and drown. Female frogs and toads are at higher risk of drowning as they are often submerged underwater by one or more males. Even today, mass toad graves are found on migration routes and near or in mating ponds. This was likely to be the same situation for the Geiseltal specimens. </p>
<p>The carcasses were moved by light currents in the swampy lakes and sank to the bottom in the cold, deep, and undisturbed regions of the lake. The cold temperatures (probably about 8°C) prevented decay and kept many skeletons in good condition. In some skeletons even small bones such as finger bones or toe bones are still well defined. </p>
<p>Some frogs may have <a href="https://journals.ametsoc.org/view/journals/clim/31/23/jcli-d-18-0129.1.xml?tab_body=abstract-display">frozen to death,</a> died from diseases or from old age. That’s information the frogs took to the grave with them as these three causes of death are difficult to verify. But after months of studying these fossils and analysing what we know about their lifestyles my team came to an astonishing conclusion. </p>
<p>The most likely explanation for why there are several groups of frogs, each numbering in the hundreds, that died almost at the same time in different ponds, is that their enthusiastic mating killed them. It explains why similar mass graves have been found in different parts of the world. </p>
<p>The German <a href="https://www.naturkundemuseum.uni-halle.de/sammlungen/geiseltal_sammlung/">Geiseltal fossil collection</a> was closed for decades but recently reopened to the public and scientists. It is an incredible time capsule of over 50,000 fossils from a former lignite (brown coal) opencast mine in the Geiseltal. </p>
<p>The fossils include crocodiles, huge snakes, flightless giant birds and dog-sized primeval horses. Many of the Geiseltal fossils are so well preserved they show remarkable details including bones, scales, skin, internal organs and gut contents. </p>
<p>The mine was flooded to create a recreational area in the early 2000s and is a giant lake now. </p>
<h2>Don’t take frogs for granted</h2>
<p>While these mating deaths sound extreme, a far more common cause of frog and toad mortality is humans destroying their homes, polluting water sources and spreading disease. </p>
<p>Frogs and toads survived several climate changes and extinction events on earth. However, some species have gone extinct. In 2021 one of the <a href="https://www.nhm.ac.uk/discover/news/2021/may/extinction-of-frog-is-a-huge-blow-to-the-diversity-of-life.html">few remaining frog species</a> of an ancient lineage of amphibians was declared likely extinct, having not been seen in 60 years. </p>
<p>A <a href="https://ipbes.net/">2019 UN report</a> showed amphibians, particularly frogs, are <a href="https://www.businessinsider.com/frogs-amphibians-dying-6th-mass-extinction-photos-2019-6?r=US&IR=T">among the hardest hit</a> by the nature crisis. Frogs can migrate short distances if environmental conditions in their pond change. But they are <a href="https://www.theguardian.com/environment/2021/jun/16/disease-causing-mass-deaths-frogs-reaches-britain-aoe">vulnerable to disease</a>, which can be <a href="https://www.science.org/doi/full/10.1126/science.aav0379">driven by human impacts on nature</a>. </p>
<p>Frogs and toads live nearly everywhere including on <a href="https://www.nwf.org/Educational-Resources/Wildlife-Guide/Amphibians/Tree-Frogs">trees</a>, <a href="https://naturebackin.com/2017/02/16/against-the-odds-finding-tree-frogs-in-flowers/">in flowers</a>, in the jungle and <a href="https://museum.wa.gov.au/explore/articles/meet-frogs-live-desert">in the desert</a>. Some look almost as colourful as a rainbow and others <a href="https://www.nationalgeographic.com/animals/amphibians/facts/wallaces-flying-frog">can even fly</a>. Imagine these creatures <a href="https://www.pnas.org/doi/10.1073/pnas.1704632114">feeding next to a T-Rex</a>. It would be a tragedy if we lost any more species.</p><img src="https://counter.theconversation.com/content/188562/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Daniel Falk receives funding from the Government of Ireland-Irish Research Council (IRC) Postgraduate Scholarship GOIPG/2018/3354. He is a PhD cancidate in the University College Cork (UCC), Ireland. The project is a collaboration of UCC and the Natural Sciences Collections of the Martin-Luther-University Halle (Saale), Germany.</span></em></p>Millions of years on. modern frogs and toads still haven’t learnt you can have too much of a good thing.Daniel Falk, Geology / Palaeontology PhD candidate, University College CorkLicensed 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>
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<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/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/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:
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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>
<figure class="align-center zoomable">
<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>
<figure class="align-center zoomable">
<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/990572018-07-04T14:24:09Z2018-07-04T14:24:09ZMake your garden frog friendly – amphibians are in decline thanks to dry ponds<figure><img src="https://images.theconversation.com/files/226141/original/file-20180704-73303-1gtda3d.jpg?ixlib=rb-1.1.0&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/marsh-frog-rana-ridibunda-single-water-145072183?src=xvavMacb92tEg844472MZg-3-5">Shutterstock</a></span></figcaption></figure><p>Garden frogs and toads are in decline. The latest data from <a href="https://www.rspb.org.uk/about-the-rspb/about-us/media-centre/press-releases/garden-survey-reveals-sightings-of-frog-and-toad-are-drying-up-in-scotland/">RSPB Garden Birdwatch</a> reveals that we are seeing one-third fewer toads and 17% fewer frogs compared to 2014. Many people forget that our gardens can be important havens for wildlife. But with ponds drying up, amphibians are losing out. </p>
<p>We should be worried about these declines. Frogs and toads may not be our most glamorous garden inhabitants, but they offer an important opportunity to connect with wildlife within a domestic environment.</p>
<p>As RSPB conservation scientist Dr Daniel Hayhow <a href="https://www.independent.co.uk/environment/uk-frogs-toads-gardens-ponds-decline-rspb-birdwatch-wildlife-a8409501.html">says</a>: </p>
<blockquote>
<p>Most people remember seeing tadpoles at the local pond or a toad emerging from under a rock while they were growing up. These first experiences with nature stay with us forever. Unfortunately, the sights and sounds of wildlife that were once common to us are sadly becoming more mysterious.</p>
</blockquote>
<p>These early connections with wildlife are being lost, leading to concerns that some children may be suffering from <a href="http://richardlouv.com/books/last-child/">nature deficit disorder</a> which can affect their mood and attention. <a href="http://science.sciencemag.org/content/295/5564/2367.2">Research shows</a> that children are more familiar with Pokémon characters than they are with our native wildlife. We need to find more ways to encourage interactions with nature. Ponds, even small ones, are a great way of doing this. </p>
<p>Population declines in amphibians is caused by the reduction of garden ponds, and the reduced numbers of ponds in the wider countryside. We <a href="https://freshwaterhabitats.org.uk/habitats/pond/">lost 50% of our ponds</a> in the UK over the 20th century, and many that are left are in a poor condition because of pollution and lack of management. </p>
<p>Frogs and toads need clean ponds in which to breed, but outside the breeding season you’ll find them in tall grass and log piles. The fashion of keeping our gardens meticulously neat and tidy is leaving our wildlife with nowhere to hide. Amphibians also provide a very useful pest control service (they love eating slugs and snails) so encouraging them into gardens could bring many benefits. </p>
<p>So how do we help? The Freshwater Habitats Trust is leading the <a href="https://freshwaterhabitats.org.uk/projects/million-ponds/">Million Ponds Project</a> with the aim of creating networks of ponds. You don’t need to rebuild your garden to get involved, as even a small outside tub can be enough to provide a suitable habitat for amphibians. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/RmdxdmlNAFY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>If you are feeling more generous, then creating a larger pond can be a fun project – especially with children. Once put in, it will only take a matter of days before something decides to make it their home. It will usually be invertebrates and plants to begin with, but it won’t take long for it to be found by a nearby frog or toad population. </p>
<h2>Pond life</h2>
<p>Another benefit of gardening with wildlife in mind, is that often it means that you need to do less work. Mowing your lawn less frequently provides a great habitat for wildlife. And creating a log pile, putting up nest boxes for birds or putting in a hole in your fence to allow access for hedgehogs, are all low-effort activities which are highly effective. </p>
<p>There are even ways to get involved if you do not have a garden. You can become a local “<a href="https://www.froglife.org/what-we-do/toads-on-roads/">toad patroller</a>”, helping toads to navigate roads safely as they migrate to their breeding ponds. Or you could become a citizen scientist by reporting whenever you see a frog or toad through <a href="https://www.arc-trust.org/report-your-sightings">Amphibian and Reptile Conservation</a>, and taking part in the <a href="https://www.rspb.org.uk/fun-and-learning/for-families/family-wild-challenge/?utm_source=promotions&utm_campaign=wildchallenge">RSPB’s Wild Challenge</a>. </p>
<p>Gardens in the UK might account for <a href="https://www.bbc.co.uk/news/uk-41901294">less than 2%</a> of our total land use, but <a href="https://www.gov.uk/government/publications/rural-population-and-migration/rural-population-201415">83% of people live in urban areas</a>. Small adjustments in gardens could lead to big changes in frog and toad populations – which would be good news for them, and provide gardeners young and old with a boost at the same time.</p><img src="https://counter.theconversation.com/content/99057/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Becky Thomas 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>As ponds dry up, so too does our connection to nature.Becky Thomas, Senior Teaching Fellow in Ecology, Royal Holloway University of LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/977282018-06-04T15:08:25Z2018-06-04T15:08:25ZAn invasion of toxic toads threatens Madagascar’s vulnerable wildlife<figure><img src="https://images.theconversation.com/files/221549/original/file-20180604-175451-zmgfog.jpg?ixlib=rb-1.1.0&rect=3%2C13%2C1274%2C754&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Ben Marshall</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Madagascar is in the midst of a toxic invasion. Since around 2010, an army of invasive Asian toads (<em>Duttaphrynus melanostictus</em>) has gained a foothold in and around the eastern port of Toamasina after they were accidentally introduced from South-East Asia. This has dismayed conservationists who worry about the island’s already <a href="http://journals.sagepub.com/doi/abs/10.1177/194008291500800210">beleaguered endemic fauna</a>. </p>
<p>Now, our worst fears have been confirmed by recent findings by a research team led by Bangor University masters student Ben Marshall and including myself. In our <a href="https://www.cell.com/current-biology/fulltext/S0960-9822(18)30452-4">new study</a> published in Current Biology, we show that most of Madagascar’s unique native wildlife can indeed be poisoned by the introduced toad.</p>
<p>Invasive species are one of the major drivers of extinction worldwide. Most impact native species by eating them (cats, rats), competing with them (grey squirrels in the UK) or altering local vegetation (rabbits, goats). Invasive toads, on the other hand, primarily affect native predators through their skin toxins, poisoning any animal that takes a toad into its mouth. “True toads”, of the family Bufonidae, synthesise <a href="https://www.ncbi.nlm.nih.gov/pubmed/6245447">potent toxins</a> in large prominent parotoid glands on their backs. These “bufotoxins” impede the regulation of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3079441/">sodium and potassium levels in cells</a>, leading to rapid heart failure and death.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/221565/original/file-20180604-175400-19bwfgg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/221565/original/file-20180604-175400-19bwfgg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/221565/original/file-20180604-175400-19bwfgg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=479&fit=crop&dpr=1 600w, https://images.theconversation.com/files/221565/original/file-20180604-175400-19bwfgg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=479&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/221565/original/file-20180604-175400-19bwfgg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=479&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/221565/original/file-20180604-175400-19bwfgg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=602&fit=crop&dpr=1 754w, https://images.theconversation.com/files/221565/original/file-20180604-175400-19bwfgg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=602&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/221565/original/file-20180604-175400-19bwfgg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=602&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Madagascar’s tree snakes are found nowhere else on Earth.</span>
<span class="attribution"><span class="source">M Vences</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Where toads occur naturally, some predators avoid them, but others have <a href="https://doi.org/10.1073/pnas.1511706112">evolved resistance</a> to their toxins, allowing them to routinely eat toads. Recent investigations have revealed the mechanism of resistance: two specific amino acid substitutions in the target molecule of bufotoxin, the ATPase sodium-potassium pump, are all that is required to change a dangerously poisonous toad into a <a href="https://doi.org/10.1073/pnas.1511706112">potential meal</a>. Remarkably, the same solution has evolved in a diverse array of species, from rats to lizards to the toads themselves, and this appears to be the only way for any vertebrate to resist the toads’ toxins.</p>
<p>The problem for Madagascar’s animals is they developed on an island with plenty of frogs but <a href="http://www.wildmadagascar.org/wildlife/frogs.html">no toads</a>. Native species therefore had no reason to evolve any resistance to toad toxins nor any sense that they should avoid toads.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/221572/original/file-20180604-175445-1hwxu16.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/221572/original/file-20180604-175445-1hwxu16.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/221572/original/file-20180604-175445-1hwxu16.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/221572/original/file-20180604-175445-1hwxu16.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/221572/original/file-20180604-175445-1hwxu16.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/221572/original/file-20180604-175445-1hwxu16.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/221572/original/file-20180604-175445-1hwxu16.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/221572/original/file-20180604-175445-1hwxu16.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">Toxic toad making friends in a Madagascar village.</span>
<span class="attribution"><span class="source">Franco Andreone</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>And when toads do invade these previously toad-free areas, it may result in mass mortality among some naive predators. For instance the infamous <a href="https://www.researchgate.net/publication/47334877_The_Ecological_Impact_of_Invasive_Cane_Toads_Bufo_Marinus_in_Australia">cane toad invasion of Australia</a> caused larger apex predators, such as monitor lizards, some snakes and the marsupial quolls to become locally rare or extinct. This in turn affected numerous other species in the food web, though some, such as some smaller lizards and snakes, actually flourished due to the removal of the larger predators.</p>
<h2>Searching for resistance</h2>
<p>So will Madagascar’s predators suffer just like Australia’s? As we now know that there is a single molecule responsible for toad resistance in vertebrates, this gives biologists an invaluable tool: simply examining the relevant gene will reveal whether an animal can eat a toad with impunity or is liable to be poisoned.</p>
<p>In our study, we used this approach on a range of Malagasy predators. The results confirmed our worst fears: out of 29 reptiles, eight mammals, 12 frogs and 28 birds tested, all except one rodent (the white-tailed antsangy) lack resistance to toad toxins.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/221568/original/file-20180604-175400-1bhxtuu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/221568/original/file-20180604-175400-1bhxtuu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/221568/original/file-20180604-175400-1bhxtuu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=421&fit=crop&dpr=1 600w, https://images.theconversation.com/files/221568/original/file-20180604-175400-1bhxtuu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=421&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/221568/original/file-20180604-175400-1bhxtuu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=421&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/221568/original/file-20180604-175400-1bhxtuu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=529&fit=crop&dpr=1 754w, https://images.theconversation.com/files/221568/original/file-20180604-175400-1bhxtuu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=529&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/221568/original/file-20180604-175400-1bhxtuu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=529&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Toad-proof: the white-tailed antsangy.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:BrachytarsomysAlbicaudataWolfSmit.jpg">Joseph Wolf & Joseph Smit</a></span>
</figcaption>
</figure>
<p>This presents an immediate conservation concern in an already troubled <a href="https://doi.org/10.1038/35002501">biodiversity hotspot</a>, and has serious implications for the many species that exist only on Madagascar. For instance, all Malagasy snakes tested are vulnerable to toad toxins, and <a href="http://www.amphibians.org/wp-content/uploads/2016/03/Asian-Toad-Feasibility-Report-26th-Jan-2016.pdf">anecdotal reports</a> have already documented snakes dying from eating toads. </p>
<p>It gets worse: in the past, a loss of snakes has led to booms in rodent populations and fears over public health. Such fears are warranted once again, given that non-native rats are <a href="https://pubs.acs.org/doi/abs/10.1021/bi00422a016">resistant to bufotoxins</a>.</p>
<p>However, rodents appear to be unique in this respect. Among the toad-sensitive mammals are Madagascar’s most charismatic and widely recognised residents. Three representatives from three lemur families are vulnerable. Fortunately lemurs eat plants and sometimes insects, and only <a href="http://repository.kulib.kyoto-u.ac.jp/dspace/handle/2433/143673">rarely prey on small vertebrates</a>, which will likely limit the toad’s impact on them. The same cannot be said for the carnivores of Madagascar: the habits of the enigmatic fossa and others make them <a href="http://eprints.kingston.ac.uk/35733/1/Brown-K-35733-AAM.pdf">extremely likely to encounter and consume</a> the toxic invader.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/221570/original/file-20180604-175407-z31ud8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/221570/original/file-20180604-175407-z31ud8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/221570/original/file-20180604-175407-z31ud8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=429&fit=crop&dpr=1 600w, https://images.theconversation.com/files/221570/original/file-20180604-175407-z31ud8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=429&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/221570/original/file-20180604-175407-z31ud8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=429&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/221570/original/file-20180604-175407-z31ud8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=539&fit=crop&dpr=1 754w, https://images.theconversation.com/files/221570/original/file-20180604-175407-z31ud8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=539&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/221570/original/file-20180604-175407-z31ud8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=539&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The cat-like fossa will eat anything from lemurs to lizards.</span>
<span class="attribution"><span class="source">Dudarev Mikhail/Shutterstock</span></span>
</figcaption>
</figure>
<p>As cane toads in Australia highlighted, it’s tough to predict <a href="https://www.ucpress.edu/book/9780520295100/cane-toad-wars">exactly which species</a> will be most affected by an invader. The sharing of habits and habitats will likely be the biggest factor influencing how much the toad will impact a species, but subtle differences in their interactions can make big differences to the outcome. For instance, <a href="https://www.researchgate.net/publication/23314953_Impact_of_the_invasive_cane_toad_Bufo_marinus_on_an_Australian_frog_Opisthodon_ornatus_depends_on_reproductive_timing">small variations in breeding times</a> made large differences in the relative success of native and invasive tadpoles in Australia.</p>
<p>Possible hope comes in the form of animals’ unrelenting ability to adapt. Australia offers <a href="https://www.researchgate.net/publication/263023395_A_small_dasyurid_predator_Sminthopsis_virginiae_rapidly_learns_to_avoid_a_toxic_invader">many examples</a> of native species evolving or learning quickly to <a href="https://academic.oup.com/beheco/article/21/5/966/197746">avoid toads</a>, or to only <a href="https://www.academia.edu/15751130/Toad_s_tongue_for_breakfast_exploitation_of_a_novel_prey_type_the_invasive_cane_toad_by_scavenging_raptors_in_tropical_Australia">eat the least toxic parts</a> of toads. Whether vulnerable Malagasy species, restricted to much more fragmented habitat patches serving as their final refuges, can display similar resilience remains to be seen.</p>
<p>The invasion of Madagascar by these toads has attracted <a href="https://www.researchgate.net/publication/262696887_Ecology_Stop_Madagascar%27s_toad_invasion_now">considerable attention</a>, but initial efforts to eliminate them have <a href="https://www.conservationevidence.com/individual-study/6851">faltered</a>. We hope that the confirmation that these toads pose a real threat to native species will reinvigorate efforts to protect native species from the toad’s further expansion.</p><img src="https://counter.theconversation.com/content/97728/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Wolfgang Wüster 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 study confirms fears that the island’s native wildlife can be poisoned by introduced Asian toads.Wolfgang Wüster, Senior Lecturer in Zoology, Bangor UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/954592018-05-01T11:02:47Z2018-05-01T11:02:47ZHow tiny toads seize the day – and the weather conditions – for breeding<figure><img src="https://images.theconversation.com/files/216246/original/file-20180425-175044-14vedfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Rose's mountain toadlets mate in small puddles. Here is a male with a string of eggs in the water.</span> <span class="attribution"><span class="source">Francois Becker</span></span></figcaption></figure><p><a href="https://www.sanbi.org/creature/rose%E2%80%99s-mountain-toadlet">Rose’s mountain toadlet</a> is a very small amphibian – adults grow to just 2 centimetres in length. These little toads can be found scattered across the mountainous, fynbos-rich biodiversity hotspot on the Cape Peninsula near Cape Town, South Africa. </p>
<p>The toadlet usually gathers to breed in a few small puddles that form during the winter rainfall season each year, in August and September. They rely on rainfall to fill their breeding puddles. But the region’s climate is altering, becoming increasingly dry. </p>
<p><a href="https://www.journals.uchicago.edu/doi/abs/10.1086/695315">New research</a> my colleagues and I recently published in <em>American Naturalist</em> shows just how much this small toad’s survival depends on weather and, more specifically, on rainfall quantity. But part of our findings were rather unexpected: the population’s adult survival rate is higher in drier years than it is in wetter years. </p>
<p>This seems counter-intuitive. Why would survival be high in dry years for a species with a life cycle that depends on water? It turns out that these little toads seize the day: they adapt their breeding habits depending on the weather. It’s an approach that’s working for the species – for now. The Cape Town area is suffering from its worst drought in a century. While our study suggests that the adult toadlets will pull through this period, there’s a good chance fewer tadpoles will reach adulthood.</p>
<p>If this current drought worsens or reoccurs because of climate change, it seems likely this species’ population will decline in the long run. Adult survival in dry years is now extremely important and unexpected events that cause adult mortality – like high predation or overgrown breeding puddles – could take a heavy toll on Rose’s mountain toadlet.</p>
<h2>Tracking the toads</h2>
<p>Our research was carried out in <a href="https://www.sanparks.org/parks/table_mountain/">Table Mountain National Park</a> over a period of seven years. We marked and recaptured individual adult male toads over this period, allowing us to track their survival. </p>
<p>During the breeding season males gather at <a href="https://www.thebhs.org/publications/the-herpetological-journal/volume-27-number-3-july-2017/1023-07-habitat-characteristics-influence-the-breeding-of-rose-s-dwarf-mountain-toadlet-i-capensibufo-rosei-i-anura-bufonidae">small puddles</a> – which are only about 20 to 30cm in diameter and around 2cm deep – waiting for females to arrive. The females come in, usually one by one, and mate with males. After laying all their eggs in the small puddle, they quickly depart. The males remain there, waiting for the next female.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/216247/original/file-20180425-175050-1d2dt6j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/216247/original/file-20180425-175050-1d2dt6j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/216247/original/file-20180425-175050-1d2dt6j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/216247/original/file-20180425-175050-1d2dt6j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/216247/original/file-20180425-175050-1d2dt6j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/216247/original/file-20180425-175050-1d2dt6j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/216247/original/file-20180425-175050-1d2dt6j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/216247/original/file-20180425-175050-1d2dt6j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Rose’s mountain toadlets – these are metamorphs, just before the adult stage – are tiny.</span>
<span class="attribution"><span class="source">Francois Becker</span></span>
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<p>This breeding strategy made it relatively easy to mark several hundred males at a breeding site each year, and to identify any males that had been marked in previous years. From this we were able to estimate an annual survival rate and to determine if the survival rate varied with rainfall.</p>
<p>Because these are amphibians, we expected survival to be higher in wetter years. Our findings proved us wrong. Here’s why.</p>
<h2>Survival of the fittest</h2>
<p>Our tracking system allowed us to see that in wet years, males stay longer at the breeding site because the puddles last longer. They wait – for days or even weeks – for females to arrive. This leaves them with little time to forage. After all, if they leave to find food they might miss their mates.</p>
<p>During their wait, the males start losing body mass. They get skinny because they don’t forage and this means that at the end of the breeding season they’ve lost their fitness. We think that makes them less likely to survive.</p>
<p>In dry years, the puddles last only a few weeks and the males depart in a healthier state without having lost body mass. They may not have reproduced, but they are still strong and so their own survival is more likely.</p>
<p>We also found more males at the breeding puddles in wet years and fewer in dry years. Although these toads are little, competition between males for access to females in a puddle is fierce. We consistently recorded mortalities in the puddles and assume that in high density wet years toadlets are more likely to be killed because of intense competition in the puddle.</p>
<p>In dry years, the number of individuals arriving to mate is lower in both sexes. This could be related to lower recruitment in dry years – that is, the number of tadpoles that metamorphose into toads. Recruitment is probably lower in dry years because the puddles desiccate faster and many tadpoles don’t make it. </p>
<p>It is possible – though it’s still speculation at this stage – that some adults chose to forgo reproduction in drier years because there is greater risk that their offspring will not survive. In wet years, recruitment is higher so it’s possible that most adults of both sexes will show up to breed.</p>
<p>Our findings are the first to show such large fluctuations in survival rates in connection with climate variability, although there is no reason to assume that this is unique to dwarf toads. For these little toads, life is precarious given that all predictions point to a rapidly warming and drying climate in southern Africa.</p><img src="https://counter.theconversation.com/content/95459/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Krystal Tolley receives funding from the South African National Biodiversity Institute. </span></em></p>The Rose’s mountain toadlet adapts its breeding habits according to the weather.Krystal Tolley, Principal Scientist, South African National Biodiversity InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/934842018-03-21T04:47:19Z2018-03-21T04:47:19ZCome hither… how imitating mating males could cut cane toad numbers<p>Cane toads are a real Aussie success story – for themselves, at least. But research has produced a new kind of trap that may help stop their insidious march south.</p>
<p>The new traps imitate cane toads’ mating calls and also use UV lights to attract insects, enticing both male and female toads to the trap. </p>
<p>There are too many toads in Australia to eradicate by simply removing individuals – some estimates put the number as high as 1.5 billion – but we hope that eliminating reproducing females could slow population growth.</p>
<h2>Toad-ally awful</h2>
<p>In 1935, 102 toads were shipped from <a href="https://theconversation.com/everyone-agreed-cane-toads-would-be-a-winner-for-australia-19881">Hawaii to Queensland</a> to help control the cane beetle that were attacking sugar cane crops. They weren’t particularly effective at that job, but they were certainly successful at spreading. </p>
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Read more:
<a href="https://theconversation.com/everyone-agreed-cane-toads-would-be-a-winner-for-australia-19881">Everyone agreed: cane toads would be a winner for Australia</a>
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<p>Although no one knows for sure exactly how many cane toads are in Australia now, we do know that they have spread from the tropical Top End, through Darwin to the Kimberley in Western Australia, west to Longreach in western Queensland, and even as far south as Sydney. </p>
<p>Cane toads <a href="https://theconversation.com/great-invaders-poison-could-also-be-its-downfall-7609">reproduce rapidly</a>, and are <a href="https://phys.org/news/2018-01-invading-toads-adjusting-rapidly-environmental.html">very adaptable</a> and extremely mobile, covering up to a kilometre a night in the <a href="http://www.publish.csiro.au/WR/WR08021">right conditions</a>. They can also hitch rides on trucks, cars and even planes (hitching a ride is probably how a cane toad ended up in Mount Kosciuszko National Park <a href="http://www.abc.net.au/news/2017-03-22/cane-toad-found-at-mount-kosciuszko-national-park/8374726">last year</a>).</p>
<p>As they spread they wreak havoc on the native environment. Toads are highly toxic, making native predators like quolls, goannas and snakes sicken or die.</p>
<p>And while the toads only eat about as many insects as native frogs of the same size, their sheer population numbers mean they are likely to reduce the food availabile for other ground-dwelling insect-eaters, such as geckos, frogs, and some small mammals. </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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<h2>Using cane toad calls to trap adult toads</h2>
<p>In our laboratory we study frog calls. Male cane toads, like most frogs and toads, make a species-specific call to attract mates. About 15 years ago, we thought it might be possible to attract toads into traps using that call – which is, after all, for <a href="http://www.publish.csiro.au/WR/WR06173">attracting females</a>. </p>
<p>To our surprise, we found that both males and females were attracted to this call, and that although males are attracted to anything that sounds even a bit like a toad, <a href="https://www.sciencedirect.com/science/article/pii/S0003347215003127">females prefer certain call types</a>. </p>
<p>We also found that toads are attracted to insects that are attracted to lights, despite the paradoxical fact that toads <a href="https://www-tandfonline-com.elibrary.jcu.edu.au/doi/abs/10.1080/09670874.2015.1058991">don’t like white lights very much</a>. </p>
<p>We solved this problem by using UV lights to attract insects without bothering the toads. We then built traps that coupled UV lights to draw in insect food for the toads with the right call type, which were <a href="https://link.springer.com/article/10.1007/s10340-014-0555-9">more successful</a> than traps without both. </p>
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<a href="https://images.theconversation.com/files/211289/original/file-20180321-80654-g2el0i.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/211289/original/file-20180321-80654-g2el0i.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/211289/original/file-20180321-80654-g2el0i.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/211289/original/file-20180321-80654-g2el0i.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/211289/original/file-20180321-80654-g2el0i.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/211289/original/file-20180321-80654-g2el0i.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/211289/original/file-20180321-80654-g2el0i.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/211289/original/file-20180321-80654-g2el0i.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">Our traps use audio recordings of male mating calls and insect-attracting UV lights to make the cage appealing to both male and female cane toads.</span>
<span class="attribution"><span class="source">Eric Nordberg</span>, <span class="license">Author provided</span></span>
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<p>James Cook University has been working with our industry partner, Animal Control Technologies Australia, to develop a functional trap people can use to get rid of adult toads. Our trap captures adult (breeding age) males and females before they reproduce, targeting future generations as well as the individuals themselves.</p>
<h2>Solving the ultimate problem</h2>
<p>Although we have known cane toads threaten our native wildlife for some time, there are still no strategies available to control their numbers, apart from removing them by hand. </p>
<p>Our research has shown that trapping is less <a href="https://www-tandfonline-com.elibrary.jcu.edu.au/doi/full/10.1080/09670874.2017.1363443">labour intensive than hand capture, and can be conducted for long periods</a>. Trapping may be useful as part of general strategies to reduce toad numbers in sensitive areas, for example on islands. <a href="https://theconversation.com/great-invaders-poison-could-also-be-its-downfall-7609">Traps for tadpoles</a> are presently being trialled around Brisbane. </p>
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Read more:
<a href="https://theconversation.com/great-invaders-poison-could-also-be-its-downfall-7609">Great invader's poison could also be its downfall</a>
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<p>Trapping may also be a good way to collect individuals to apply any control methods invented in the future. This may be a genetically engineered disease, or ongoing efforts to genetically alter toads to make them <a href="https://www.journals.uchicago.edu/doi/abs/10.1086/692167">non-toxic</a>. </p>
<p>Other mitigation strategies currently being tested include <a href="https://theconversation.com/teaching-reptiles-to-avoid-cane-toads-earns-top-honour-in-pms-science-prizes-67306">training native species not to eat toads</a>, either directly or using distasteful baits, and establishing <a href="https://theconversation.com/building-fences-could-stop-cane-toads-in-their-tracks-37092">natural dry barriers</a> that slow toad spread.</p>
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Read more:
<a href="https://theconversation.com/building-fences-could-stop-cane-toads-in-their-tracks-37092">Building fences could stop cane toads in their tracks</a>
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<p>We hope that traps for adults will become part of an arsenal of methods available to combat these pests, both at and behind the invasion front.</p><img src="https://counter.theconversation.com/content/93484/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lin Schwarzkopf works in partnership with Animal Control Technologies Australia, a for-profit company that partners with James Cook University via a Linkage grant. This cane toad research was also funded by a Caring for Country grant from the federal government.</span></em></p>New cane toad traps that carefully imitate mating males successfully target breeding females. Males, meanwhile, will turn up for anything that sounds remotely like a toad.Lin Schwarzkopf, Professor in Zoology, James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/912882018-02-07T00:03:26Z2018-02-07T00:03:26ZHow bombardier beetles survive being eaten – and other amazing animal defence mechanisms<p>In Disney’s film version of Pinnochio, the boy-puppet rescues his creator Geppetto by lighting a fire inside Monstro the whale, who has swallowed them both. The fire causes the whale to sneeze, freeing Pinnochio and Geppetto from their gastric prison.</p>
<p>Before you dismiss this getaway as incredible fantasy, consider that new research shows that a kind of fire in the belly can actually be an effective strategy for escaping predators in the real world. In fact, the animal kingdom is full of amazing examples of unusual defence mechanisms that help small creatures avoid a nasty fate.</p>
<p>In a new paper <a href="http://rsbl.royalsocietypublishing.org/lookup/doi/10.1098/rsbl.2017.0647">in Biology Letters</a>, scientists at Kobe University in Japan describe how bombardier beetles can survive being eaten by a toad by releasing a hot chemical spray that makes the hungry amphibian vomit.</p>
<p>Bombardier beetles are so-named because, when threatened, they emit a boiling, irritating substance from their backsides <a href="http://news.bbc.co.uk/2/hi/science/nature/422599.stm">with remarkable accuracy</a>, to deter potential predators. They produce the caustic mixture by <a href="https://www.wired.com/2014/05/absurd-creature-of-the-week-bombardier-beetle/">combining hydrogen peroxide, hydroquinones and chemical catalysts</a> in a specially reinforced chamber at the base of their abdomen, which shields the beetle’s own organs from the resulting explosive reaction.</p>
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<p><a href="http://rsbl.royalsocietypublishing.org/lookup/doi/10.1098/rsbl.2017.0647">The Japanese researchers</a> fed two different species of bombardier beetles to captive toads. They were then able to confirm that the beetles used their weapon inside the toads by listening carefully for the explosive pop that accompanies each discharge. </p>
<p>Toads are ambush predators, quite used to swallowing first and asking questions later. When they start to feel a dose of diner’s remorse, they can literally turn <a href="https://indianapublicmedia.org/amomentofscience/how-to-heave-your-guts/">their stomachs inside out and scrape out the contents</a>, rather than suffering meekly from indigestion. Many of the toads in this experiment did just that, disgorging the beetles up to 107 minutes after ingestion. Remarkably, the ejected beetles all survived.</p>
<p>In a further experiment, the researchers poked beetles with forceps to deplete their spray reserves. Compared to those with full tanks of fuel, the exhausted beetles were much less likely to be ejected. This showed that it really was their chemical arsenals that saved them, rather than just their taste or behaviour in the gut.</p>
<figure> <img src="https://media.giphy.com/media/26DN4S3rQgsgvzEY0/giphy.gif"><figcaption>“I guess I’ll die another day.” Sugiura & Sato, Kobe University</figcaption></figure>
<p>The bombardier beetle is of course not the only animal escape artist. The diverse getaway tactics of animals are a testament to the fascinating creativity of evolution. Subject to millions of years of abuse and exploitation by predators, natural selection has shaped an array of ingenious strategies for cheating death in the face of would-be devourers.</p>
<h2>Animal Houdinis</h2>
<p>Some examples are probably familiar to most people. For instance, many lizards drop their tails to distract a predator or <a href="https://academic.oup.com/bioscience/article/59/8/728/256547">escape from its venom</a>. But others are more exotic. Sea cucumbers don’t have tails so they <a href="http://echinoblog.blogspot.ca/2012/01/sea-cucumber-evisceration-defense.html">eject and regenerate their internal organs instead</a>. Loud sounds (<a href="http://thatslifesci.com.s3-website-us-east-1.amazonaws.com/2016-12-26-How-Pistol-Shrimp-Kill-With-Bubbles-AStrauss/">such as the “gunshots” of snapping shrimp</a>) and bright colours (as on <a href="https://www.ucpress.edu/ebook.php?isbn=9780520952461">banded wing grasshoppers</a>) are also effective means of <a href="https://pdfs.semanticscholar.org/5742/afd010a4e1b889d1097f28f6f5741f10d33e.pdf">startling predators</a>. Mantid insects unite movement, sound and colour in an elaborate display that can stop an attack or at least give them a chance to escape.</p>
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<p>Some animals fight back, such as the frogs that can <a href="http://rsbl.royalsocietypublishing.org/content/4/4/355">erect sharp bony splinters</a> from their claws that <a href="https://www.newscientist.com/article/dn13991-horror-frog-breaks-own-bones-to-produce-claws/">pierce their own skin</a>, like X-Men’s Wolverine. Other animals, including <a href="https://doi.org/10.1098%252Frspb.2001.1708">the mimic octopus</a>, prefer to pretend to be being dangerous, <a href="https://www.nature.com/scitable/blog/accumulating-glitches/the_mimic_octopus_master_of">adopting the appearance of more deadly prey</a> when threatened.</p>
<p>The stunning variety of defensive mechanisms would be impressive even if we only counted variations of chemical warfare, similar to the bombardier beetle’s steam treatment. There are the defensive toxins in <a href="https://www.nationalgeographic.com/animals/fish/group/pufferfish/">pufferfish</a> and <a href="http://www.bbc.com/earth/story/20150422-the-worlds-most-poisonous-animal">poison arrow frogs</a>, the nauseating <a href="https://www.newscientist.com/article/mg12717282-900-science-the-seven-deadly-smells-of-a-skunk/">odours of skunks</a>, the charmingly named but actually revolting <a href="http://www.bbc.com/earth/story/20150623-millipedes-use-chemical-weapons">repugnatorial glands of some millipedes</a>, and the <a href="http://www.nydailynews.com/life-style/vomit-bird-throws-defense-predators-eurasian-roller-nestlings-emit-foul-smelling-fluid-protection-article-1.1037423">projectile vomiting</a> and <a href="https://wildfowl.wwt.org.uk/index.php/wildfowl/article/view/562">faecal egg decorating</a> of some birds.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/205061/original/file-20180206-14107-1lzimnd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/205061/original/file-20180206-14107-1lzimnd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/205061/original/file-20180206-14107-1lzimnd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/205061/original/file-20180206-14107-1lzimnd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/205061/original/file-20180206-14107-1lzimnd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/205061/original/file-20180206-14107-1lzimnd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/205061/original/file-20180206-14107-1lzimnd.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">
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<span class="caption">I wouldn’t eat me if I were you.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/strawberry-poison-dart-frog-dendrobates-pumilio-110478725?src=wsqFvxedepyW5_6CPNI-NQ-1-3">Maiquez/Shutterstock</a></span>
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<p>Why should nature have created such an impressive array of defensive tactics? One possible explanation can be summarised as the <a href="http://evosophos.com/life-dinner-principle/">life-dinner principle</a>, articulated by biologists <a href="http://rspb.royalsocietypublishing.org/content/205/1161/489">Richard Dawkins and John Krebs in the late 1970s</a>. The argument is that predator and prey often face asymmetrical selection pressures, meaning that the stakes are different for the two competitors. If a predator fails to capture its target, it loses dinner, but if the prey fails to escape, it loses its life. Because the stakes are greater for prey, we shouldn’t be surprised they have developed so many impressive defences.</p>
<p>Understanding nature’s tremendous capacity to adapt should make us be careful. Humans interact with other organisms all the time, and usually we’re the predators. When we try to take action against other creatures to stop them spreading disease or eating crops, we should be mindful that evolutionary innovation can produce remarkable adaptations. For example, our widespread use of <a href="https://www.myjoyonline.com/lifestyle/2018/february-3rd/high-levels-of-antibiotic-resistance-found-worldwide-who.php">antibiotics</a> and <a href="https://guardian.ng/features/malaria-cases-rise-as-insecticide-resistance-spreads/">pesticides</a> has spurred the evolution of organisms that are resistant to these methods.</p>
<p>Only by having a healthy respect for the relentless power of evolution can we hope to generate sustainable solutions to these kinds of problems. If we grow complacent and inattentive, we may some day soon find ourselves facing newly evasive diseases and pests, sputtering to breathe and dyspeptic amid all the fire and smoke in our bellies.</p><img src="https://counter.theconversation.com/content/91288/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Luc Bussiere 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>Meet the brawny bug with a concoction so caustic it’ll make a toad vomit.Luc Bussiere, Lecturer in Biological Sciences, University of StirlingLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/817392017-09-20T03:15:59Z2017-09-20T03:15:59ZSaving amphibians from a deadly fungus means acting without knowing all the answers<figure><img src="https://images.theconversation.com/files/186613/original/file-20170919-22613-bbobzd.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A male boreal toad waits for opportunities to mate near a Colorado mountain lake. </span> <span class="attribution"><span class="source">Brittany Mosher</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>The calls of frogs on warm nights in the spring are a welcome sound, telling listeners that the seasons are changing and summer is coming. Today, however, ponds that once echoed with the <a href="https://www.youtube.com/watch?v=A6-8pC8o5fw">chirps</a>, <a href="https://www.youtube.com/watch?v=VAdJApsDYwM">chuckles</a> and <a href="https://www.youtube.com/watch?v=uOQ_dehNgnw">calls</a> of frogs and toads are falling silent around the world. </p>
<p>This loss is worrying. Amphibians are the environment’s canaries in the coal mine. Their declines provide early warning signs to scientists that stressors like habitat loss, climate change, pollution and disease are making ecosystems unhealthy. Without amphibians, insect and algae populations multiply, causing cascading effects on other organisms – including humans.</p>
<p><a href="https://www.newscientist.com/article/mg19726443-300-habitat-loss-drives-decline-in-amphibians/">Almost half of all amphibian species on Earth are declining</a>, and a disease called chytridiomycosis is one culprit. We work with a team of scientists and resource managers who are trying to keep amphibian populations healthy in the face of this disease. </p>
<p>Good science always involves uncertainty, but <a href="https://theconversation.com/saving-javan-rhinos-from-extinction-starts-with-counting-them-and-its-not-easy-75688">uncertainty makes it hard</a> for managers to decide <a href="https://theconversation.com/galapagos-giant-tortoises-make-a-comeback-thanks-to-innovative-conservation-strategies-67591">which of many</a> <a href="https://theconversation.com/saving-javan-rhinos-from-extinction-starts-with-counting-them-and-its-not-easy-75688">possible actions</a> to take. Moreover, while scientists do field work, analyze data and present results, government agencies and other land managers typically make the decisions about how to conserve species. However, we have learned that when these groups work together, we can move toward solutions step by step.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/186636/original/file-20170919-22632-17ks4he.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/186636/original/file-20170919-22632-17ks4he.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/186636/original/file-20170919-22632-17ks4he.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=312&fit=crop&dpr=1 600w, https://images.theconversation.com/files/186636/original/file-20170919-22632-17ks4he.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=312&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/186636/original/file-20170919-22632-17ks4he.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=312&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/186636/original/file-20170919-22632-17ks4he.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=392&fit=crop&dpr=1 754w, https://images.theconversation.com/files/186636/original/file-20170919-22632-17ks4he.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=392&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/186636/original/file-20170919-22632-17ks4he.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=392&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Global distribution of threatened amphibian species.</span>
<span class="attribution"><a class="source" href="http://www.iucnredlist.org/initiatives/amphibians/analysis/geographic-patterns">IUCN</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Confronting an ‘amphibian apocalypse’</h2>
<p>The word “amphibian” has Greek roots and means “double life.” These aptly named creatures split their time between water and land. Many amphibians use their sponge-like skin to breathe and absorb nutrients, so they are sentinels of environmental changes in both habitats.</p>
<p>The frog infection chytridiomycosis is caused by a fungus known as Bd, short for <em>Batrachochytrium dendrobatidis</em> and popularly known as chytrid fungus. Like amphibians, Bd has several life stages: a swimming spore that lives in water and an encysted form that occurs on frogs’ and toads’ sensitive skin. Infected animals grow lethargic and malnourished, often dying within weeks.</p>
<p>Several of the world’s most extraordinary amphibian species have already gone extinct due to chytridiomycosis, including the stranger-than-fiction <a href="http://www.iucnredlist.org/details/19475/0">gastric-brooding frog</a> (which reared offspring in its mouth) and the beautiful <a href="http://www.iucnredlist.org/details/54563/0">Panamanian golden frog</a>. Hundreds of other species are on the brink of extinction. Eradicating Bd is likely impossible, so we need to take alternative management actions to bolster amphibian populations if we want to see them survive.</p>
<p>Scientists have learned a great deal about Bd and its impacts over the past 20 years. Researchers know that some <a href="http://dx.doi.org/10.3354/dao068047">Bd strains</a> are more dangerous than others; that some amphibians are genetically <a href="http://dx.doi.org/10.1073/pnas.1106893108">resistant</a> or have <a href="http://www.smithsonianmag.com/science-nature/meet-colorful-new-weapon-scientists-are-using-save-toads-devastating-fungus-180961462/">other mechanisms</a> that help them tolerate infection; and that environmental differences can create <a href="http://dx.doi.org/10.1111/acv.12199">drastically different</a> disease dynamics. </p>
<p>Researchers have called the disease-related decline of amphibians an <a href="https://doi.org/10.1016/S0262-4079(12)61761-8">apocalypse</a> that requires an <a href="http://dx.doi.org/10.1126/science.1128396">unprecedented conservation response</a>. But despite great advances in knowledge about Bd and amphibians, no one has identified consistent, effective actions that we can use to halt or reverse these declines.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/186258/original/file-20170916-13360-10m2vym.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/186258/original/file-20170916-13360-10m2vym.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/186258/original/file-20170916-13360-10m2vym.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=462&fit=crop&dpr=1 600w, https://images.theconversation.com/files/186258/original/file-20170916-13360-10m2vym.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=462&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/186258/original/file-20170916-13360-10m2vym.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=462&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/186258/original/file-20170916-13360-10m2vym.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=581&fit=crop&dpr=1 754w, https://images.theconversation.com/files/186258/original/file-20170916-13360-10m2vym.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=581&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/186258/original/file-20170916-13360-10m2vym.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=581&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 life cycle of Bd starts with an aquatic spore that burrows into the skin of amphibians.</span>
<span class="attribution"><a class="source" href="https://flic.kr/p/nviYJe">Brian Gratwicke</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Knowing enough to act</h2>
<p>For the past three years, we have been part of a team tasked with merging science with management in an effort to save <a href="http://blog.sustainability.colostate.edu/?q=mosher">boreal toads</a>, which live at high elevations in the Rocky Mountains. Juvenile toads are the size of your fingernail, but eventually grow as large as baseballs when they are sexually mature. They spend more than half of their lives buried in snow, waiting for opportunities to feed and breed in spring. Boreal toads are highly susceptible to Bd and now occupy only a fraction of their former range.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/181427/original/file-20170808-21888-tks8t1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/181427/original/file-20170808-21888-tks8t1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/181427/original/file-20170808-21888-tks8t1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/181427/original/file-20170808-21888-tks8t1.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/181427/original/file-20170808-21888-tks8t1.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/181427/original/file-20170808-21888-tks8t1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/181427/original/file-20170808-21888-tks8t1.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/181427/original/file-20170808-21888-tks8t1.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 researcher swabs the skin of a boreal toad to test for chytrid fungus.</span>
<span class="attribution"><span class="source">Brittany A. Mosher</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><a href="http://cpw.state.co.us/learn/Pages/ResearchBorealToad.aspx">The Boreal Toad Conservation Team</a> includes resource managers from federal and state agencies in Colorado, Wyoming and New Mexico and <a href="http://biodiversity.colostate.edu/people/larissa-bailey">scientists from Colorado State University</a> and the U.S. Geological Survey. The team used research on current toad populations to help predict how toads might fare in the future under various possible management actions. It was humbling and exhilarating to see our work used to make decisions that might influence the fate of a species. But we wondered whether “our” science was truly the best available, and whether our team would make the “right” decision – or even have enough information to know which choice was most likely to succeed.</p>
<p>Our <a href="http://dx.doi.org/10.1111/conl.12393">action plan</a>, recently published in Conservation Letters, proposes multiple strategies, including reintroducing toads to wetlands in Colorado; managing wetland habitats to prevent them from drying out; and slowing the spread of Bd by requiring researchers to carefully disinfect boots and gear after visiting a wetland.</p>
<h2>No single solution</h2>
<p>We have found that <a href="http://www.kunc.org/post/colorado-works-save-boreal-toads-one-pond-time">relocating captive-reared boreal toads</a> is an especially effective strategy and shows some promise of successfully restoring this mountain resident to its high-elevation ecosystem. Lessons from our research will help other scientists find effective strategies for monitoring and making decisions in areas where Bd may spread. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/186257/original/file-20170916-25673-1y78coe.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/186257/original/file-20170916-25673-1y78coe.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/186257/original/file-20170916-25673-1y78coe.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/186257/original/file-20170916-25673-1y78coe.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/186257/original/file-20170916-25673-1y78coe.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/186257/original/file-20170916-25673-1y78coe.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/186257/original/file-20170916-25673-1y78coe.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">Researchers carefully monitor tadpoles that they have introduced to a site in Rocky Mountain National Park. Eggs are collected from the wild, reared to tadpole age in captivity, and then carried in backpacks filled with water to the reintroduction site.</span>
<span class="attribution"><span class="source">Brittany A. Mosher</span></span>
</figcaption>
</figure>
<p>For example, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4341422/">Bd has recently spread to Madagascar</a>, a mega-biodiversity hotspot with about 300 frog species, nearly all of which are found nowhere else on Earth. Our work could help managers in Madagascar formulate a <a href="https://link.springer.com/article/10.1007/s10393-013-0869-8">national monitoring plan</a> and prioritize strategies for conserving amphibian populations.</p>
<p>Wildlife diseases are <a href="http://dx.doi.org/10.3201/eid2301.161452">notoriously hard to study and act on</a> because they are new and complicated problems. At the start, scientists may not even be able to differentiate helpful actions from those which might be harmful. We have learned that it is rare that one single action will save a species. Rather, conservation is a learning process and a product of many actions and people. And the promise of restoring singing frogs to silent ponds is a powerful incentive for all of us to keep learning.</p><img src="https://counter.theconversation.com/content/81739/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brittany Mosher receives funding from the US Geological Survey's Amphibian Research and Monitoring Initiative. </span></em></p><p class="fine-print"><em><span>Brian Gerber receives funding from the National Park Service and Colorado Parks and Wildlife.</span></em></p><p class="fine-print"><em><span>Larissa Bailey receives funding from US Geological Survey's Amphibian Research and Monitoring Initiative, the National Park Service, and Colorado Parks and Wildlife. </span></em></p>Frogs and toads are declining around the world, with many species on the brink of extinction. Acting in time means trying strategies without complete information about how likely they are to work.Brittany A. Mosher, Postdoctoral Researcher, Colorado State UniversityBrian Gerber, Assistant Professor of Natural Resources Science, University of Rhode IslandLarissa Bailey, Associate Professor of Fish, Wildlife and Conservation Biology, Colorado State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/720642017-02-01T00:02:26Z2017-02-01T00:02:26ZThe frog tongue is a high-speed adhesive<figure><img src="https://images.theconversation.com/files/154678/original/image-20170130-7894-20l6t5.jpg?ixlib=rb-1.1.0&rect=5%2C410%2C3384%2C2273&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Gotcha, five times faster than the blink of an eye. </span> <span class="attribution"><span class="source">Candler Hobbs/Georgia Tech</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>How does one get stuck studying frog tongues? Our study into the sticky, slimy world of frogs all began with a <a href="https://www.youtube.com/watch?v=LbNl3J8HXw4">humorous video</a> of a real African bullfrog lunging at fake insects in a mobile game. This frog was clearly an expert at gaming; the speed and accuracy of its tongue could rival the thumbs of texting teenagers.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/LbNl3J8HXw4?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The frog that was the genesis of the authors’ tongue research.</span></figcaption>
</figure>
<p>Further YouTube research yielded amazing videos of frogs eating <a href="https://www.youtube.com/watch?v=6AILF4Spwpo">mice</a>, <a href="https://www.youtube.com/watch?v=b-K0KcbUWmI">tarantulas</a> and even other <a href="https://www.youtube.com/watch?v=2kwrWl8zWdg">frogs</a>. </p>
<p>The versatile frog tongue can grab wet, hairy and slippery surfaces with equal ease. It does a lot better than our engineered adhesives – not even household tapes can firmly stick to wet or dusty surfaces. What makes this tongue even more impressive is its speed: Over 4,000 species of frog and toad <a href="http://psycnet.apa.org/psycinfo/1990-97523-000">snag prey faster than a human can blink</a>. What makes the frog tongue so uniquely sticky? <a href="http://dx.doi.org/10.1098/rsif.2016.0764">Our group aimed to find out</a>.</p>
<h2>Baseline frog tongue knowledge</h2>
<p>Early modern scientific attention to frog tongues came in 1849, when biologist Augustus Waller published the <a href="http://dx.doi.org/10.1098/rstl.1849.0010">first documented frog tongue study</a> on nerves and papillae – the surface microstructures found on the tongue. Waller was fascinated with the soft, sticky nature of the frog tongue and what he called:</p>
<blockquote>
<p>“the peculiar advantages possessed by the tongue of the living frog…the extreme elasticity and transparency of this organ induced me to submit it to the microscope.”</p>
</blockquote>
<p>Fast-forward 165 years, when biomechanics researchers Kleinteich and Gorb were the first to <a href="http://dx.doi.org/10.1038/srep05225">measure tongue forces in the horned frog</a> <em>Ceratophrys cranwelli</em>. They found in 2014 that frog adhesion forces can reach up to 1.4 times the body weight. That means the sticky frog tongue is strong enough to lift nearly twice its own weight. They postulated that the <a href="http://dx.doi.org/10.1098/rsos.150333">tongue acts like sticky tape or a pressure-sensitive adhesive</a> – a permanently tacky surface that adheres to substrates under light pressure.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/155018/original/image-20170131-3244-7r5phb.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/155018/original/image-20170131-3244-7r5phb.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/155018/original/image-20170131-3244-7r5phb.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/155018/original/image-20170131-3244-7r5phb.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/155018/original/image-20170131-3244-7r5phb.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/155018/original/image-20170131-3244-7r5phb.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/155018/original/image-20170131-3244-7r5phb.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/155018/original/image-20170131-3244-7r5phb.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">Frog tongue holding up a petri dish just with its stickiness.</span>
<span class="attribution"><span class="source">Alexis Noel/Georgia Tech</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>To begin our own study on sticky frog tongues, we filmed various frogs and toads eating insects using high-speed videography. We found that the frog’s tongue is able to capture an insect in under 0.07 seconds, five times faster than a human eye blink. In addition, insect acceleration toward the frog’s mouth during capture can reach 12 times the acceleration of gravity. For comparison, astronauts normally experience around three times the acceleration of gravity during a rocket launch.</p>
<h2>On to the materials testing</h2>
<p>Thoroughly intrigued, we wanted to understand how the sticky tongue holds onto prey so well at high accelerations. We first had to gather some frog tongues. Here at Georgia Tech, we tracked down an on-campus biology dissection class, who used <a href="https://en.wikipedia.org/wiki/Northern_leopard_frog">northern leopard frogs</a> on a regular basis.</p>
<p>The plan was this: Poke the tongue tissue to determine softness, and spin the frog saliva between two plates to determine viscosity. Softness and viscosity are common metrics for comparing solid and fluid materials, respectively. Softness describes tongue deformation when a stretching force is applied, and viscosity describes saliva’s resistance to movement. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/155021/original/image-20170131-3269-v89zmh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/155021/original/image-20170131-3269-v89zmh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/155021/original/image-20170131-3269-v89zmh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1067&fit=crop&dpr=1 600w, https://images.theconversation.com/files/155021/original/image-20170131-3269-v89zmh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1067&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/155021/original/image-20170131-3269-v89zmh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1067&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/155021/original/image-20170131-3269-v89zmh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1340&fit=crop&dpr=1 754w, https://images.theconversation.com/files/155021/original/image-20170131-3269-v89zmh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1340&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/155021/original/image-20170131-3269-v89zmh.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">When the indentation head pulls away from the tongue, it adheres and stretches.</span>
<span class="attribution"><span class="source">Alexis Noel/Georgia Tech</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Determining the softness of frog tongue tissue was no easy task. We had to create our own indentation tools since the tongue softness was beyond the capabilities of the traditional materials-testing equipment on campus. We decided to use an indentation machine, which pokes biological materials and measures forces. The force-displacement relationship can then describe softness based on the indentation head shape, such as a cylinder or sphere.</p>
<p>However, typical heads for indentation machines can cost US$500 or more. Not wanting to spend the money or wait on shipping, we decided to make our own spherical and flat-head indenters from stainless steel earrings. After our tests, we found frog tongues are about as soft as brain tissue and 10 times softer than the human tongue. Yes, we tested brain and human tongue tissue (post mortem) in the lab for comparison.</p>
<p>For testing saliva properties, we ran into a problem: The machine that would spin frog saliva required about one-fifth of a teaspoon of fluid to run the test. Sounds small, but not in the context of collecting frog spit. Amphibians are unique in that they <a href="http://dx.doi.org/10.1111/j.1463-6395.1969.tb00527.x">secrete saliva through glands located on their tongue</a>. So, one night we spent a few hours scraping 15 dead frog tongues to get a saliva sample large enough for the testing equipment.</p>
<p>How do you get saliva off a frog tongue? Easy. First, you pull the tongue out of the mouth. Second, you rub the tongue on a plastic sheet until a (tiny) saliva globule is formed. Globules form due to the long-chain mucus proteins that exist in the frog saliva, much like human saliva; these <a href="http://dx.doi.org/10.1007/BF00305337">proteins tangle like pasta when swirled</a>. Then you quickly grab the globule using tweezers and place it in an airtight container to reduce evaporation.</p>
<p>After testing, we were surprised to find that the saliva is a two-phase viscoelastic fluid. The two phases are dependent on how quickly the saliva is sheared, when resting between parallel plates. At low shear rates, the saliva is very thick and viscous; at high shear rates, the frog saliva becomes thin and liquidy. This is similar to paint, which is easily spread by a brush, yet remains firmly adhered on the wall. Its these two phases that give the saliva its reversibility in prey capture, for adhering and releasing an insect.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/26xFAMpG2R8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A South American horned frog demonstrates capturing a cricket in this slow motion video.</span></figcaption>
</figure>
<h2>To catch a cricket</h2>
<p>How does soft tissue and a two-phase saliva help the frog tongue stick to an insect? Let’s walk through a prey-capture scenario, which begins with a frog tongue zooming out of the mouth and slamming into an insect.</p>
<p>During this impact phase, the tongue deforms and wraps around the insect, increasing contact area. The saliva becomes liquidy, penetrating the insect cracks. As the frog pulls its tongue back into the mouth, the tissue stretches like a spring, reducing forces on the insect (similar to how a bungee cord reduces forces on your ankle). The saliva returns to its thick, viscous state, maintaining high grip on the insect. Once the insect is inside the mouth, the eyeballs push the insect down the throat, causing the saliva to once again become thin and liquidy. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/fwThZXXXdTc?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Frogs’ eyeballs actually help them swallow their food by physically pushing what’s in the mouth back into the throat.</span></figcaption>
</figure>
<p>It’s possible that <a href="http://dx.doi.org/10.1098/rsif.2016.0764">untangling the adhesion secrets of frog tongues</a> could have future applications for things like high-speed adhesive mechanisms for conveyor belts, or fast grabbing mechanisms in soft robotics.</p>
<p>Most importantly, this work provides valuable insight into the biology and function of amphibians – 40 percent of which are in <a href="http://www.iucnredlist.org">catastrophic decline or already extinct</a>. Working with conservation organization <a href="http://www.amphibianfoundation.org">The Amphibian Foundation</a>, we had access to live and preserved species of frog. The results of our research provide us with a greater understanding of this imperiled group. The knowledge gathered on unique functions of frog and toad species can inform conservation decisions for managing populations in dynamic and declining ecosystems.</p>
<p>While it’s not easy being green, a frog may find comfort in the fact that its tongue is one amazing adhesive.</p>
<hr>
<p><em>Mark Mandica of <a href="http://www.amphibianfoundation.org">The Amphibian Foundation</a> collaborated on the <a href="http://dx.doi.org/10.1098/rsif.2016.0764">research published in Journal of the Royal Society Interface</a> and coauthored this article.</em></p><img src="https://counter.theconversation.com/content/72064/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>This material is based upon work supported by the National Science Foundation Graduate Research Fellowship (DGE-1148903).</span></em></p><p class="fine-print"><em><span>David Hu 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>How do a frog’s tongue and saliva work together to be sticky enough to lift 1.4 times the animal’s body weight? Painstaking lab work found their spit switches between two distinct phases to nab prey.Alexis Noel, PhD Student in Biomechanics, Georgia Institute of TechnologyDavid Hu, Associate Professor of Mechanical Engineering and Biology, Adjunct Associate Professor of Physics, Georgia Institute of TechnologyLicensed as Creative Commons – attribution, no derivatives.