tag:theconversation.com,2011:/us/topics/animal-extinction-27695/articlesAnimal extinction – The Conversation2024-01-17T09:05:15Ztag:theconversation.com,2011:article/2207192024-01-17T09:05:15Z2024-01-17T09:05:15ZWe are losing tetrapod species at a faster rate than we are rediscovering them<figure><img src="https://images.theconversation.com/files/569552/original/file-20240116-22672-a3vxe4.jpeg?ixlib=rb-1.1.0&rect=8%2C20%2C1908%2C1256&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Voeltzkow’s chameleon was rediscovered in Madagascar in 2018.</span> <span class="attribution"><a class="source" href="https://www.inaturalist.org/observations/2583347">Martin Mandák/iNaturalist </a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Lost species are those that have not been observed in the wild for over ten years, despite searches to find them. Lost tetrapod species (four-limbed vertebrate animals including amphibians, birds, mammals and reptiles) are a global phenomenon – there are more than 800 of them, and they are broadly distributed worldwide.</p>
<p><a href="https://onlinelibrary.wiley.com/doi/10.1111/gcb.17107">Our research</a>, published today in the journal <em>Global Change Biology</em>, attempts to pin down why certain tetrapod species are rediscovered but others not. It also reveals that the number of lost tetrapod species is increasing decade-on-decade. This means that despite many searches, we are losing tetrapod species at a faster rate than we are rediscovering them. In particular, rates of rediscovery for lost amphibian, bird and mammal species have slowed in recent years, while rates of loss for reptile species have increased.</p>
<p>This is not good news. Species are often lost because their populations have shrunk to a very small size due to human threats like hunting and pollution. Consequently, many lost species are in danger of becoming extinct (in fact, some probably are extinct). However, it is difficult to protect lost species from extinction because we don’t know where they are.</p>
<h2>Rediscoveries lead to conservation action</h2>
<p>In 2018, researchers in Colombia successfully searched for the <a href="https://www.iucnredlist.org/species/22735460/181746724">Antioquia brush-finch</a> (<em>Atlapetes blancae</em>), a bird species unrecorded since 1971. This rediscovery led to <a href="https://www.rainforesttrust.org/urgent-projects/last-stand-for-the-antioquia-brush-finch/">the establishment of a reserve</a> to protect the remaining population of the brush-finch, which is tiny and threatened by habitat loss caused by agricultural expansion and climate change.</p>
<p>The <a href="https://www.smithsonianmag.com/smart-news/scientists-find-the-extinct-victorian-earless-dragon-not-seen-since-1969-180982440/">Victorian grassland earless dragon</a> (<em>Tympanocryptis pinguicolla</em>) was rediscovered in Australia last year. It hadn’t been recorded for 54 years, and was presumed to be extinct, due to the loss of its grassland habitat and predation by invasive alien species including feral cats. Its rediscovery resulted in <a href="https://minister.dcceew.gov.au/plibersek/media-releases/joint-media-release-reptile-thought-be-extinct-rediscovered-victoria">government funding</a> to trial new survey techniques to find further populations of the species, a breeding program, and the preparation of a species recovery plan.</p>
<p>Thus, rediscoveries are important: they provide evidence of the continued existence of highly threatened species, prompting funding for conservation action. The results or our study may help to prioritise searches for lost species. In the image below, we mapped their global distribution, identifying regions with many lost and few rediscovered species.</p>
<h2>What factors influence rediscovery?</h2>
<p>Sadly, many quests to find lost species are unsuccessful. In 1993, searches in Ghana and the Ivory Coast over seven years failed to rediscover a lost primate, <a href="https://www.science.org/content/article/where-have-you-gone-miss-waldrons-red-colobus">Miss Waldron’s red colobus</a> (<em>Piliocolobus waldronae</em>). The research team concluded that this noisy and conspicuous monkey, unrecorded since 1978, may well be extinct. Its demise has been caused by hunting and the destruction of its forest habitat. Further searches in 2005, 2006 and 2019 were also unsuccessful, although <a href="https://iucn.org/resources/publication/red-colobus-piliocolobus-conservation-action-plan-2021-2026">calls that were possibly by this species were heard in 2008</a>.</p>
<p>In 2010, searches for the Mesopotamia beaked toad (<em>Rhinella rostrata</em>), unrecorded in Colombia since 1914, were unsuccessful (<a href="https://news.mongabay.com/2010/11/pictures-mr-burns-frog-discovered-in-colombia-along-with-2-other-new-species/">but did lead to the discovery of three new amphibian species</a>). Last year’s search for the <a href="https://www.rewild.org/lost-species/sinu-parakeet">Sinú parakeet</a> (<em>Pyrrhura subandina</em>), unrecorded in Colombia since 1949, was also unsuccessful. Nevertheless, the project team did identify the presence of <a href="https://www.birdguides.com/articles/conservation/exciting-rediscoveries-boost-hopes-of-finding-sinu-parakeet/">ten other parrot species in the survey area and large tracts of suitable habitat</a>, giving hope for the continued existence of the Sinú parakeet.</p>
<p>So why is it that some species are rediscovered while others remain lost? Are there specific factors that influence rediscovery? We aimed to answer these questions in our study, in order to improve our ability to distinguish between the types of lost species we can rediscover, from those that we cannot, because they are extinct.</p>
<p>Our project team comprised members of the organisation <a href="https://www.rewild.org/lost-species">Re:wild</a>, which has been leading efforts to search for lost species since 2017, along with species experts from the <a href="https://www.iucn.org/our-union/commissions/species-survival-commission">International Union for Conservation of Nature (IUCN) Species Survival Commission</a> (SSC).</p>
<p>We compiled <a href="https://doi.org/10.5061/dryad.c866t1gdf">a database of 856 lost and 424 rediscovered tetrapod species</a> (amphibians, birds, mammals and reptiles). We then proposed three broad hypotheses about factors that might influence rediscovery: characteristics of (i) tetrapod species, and (ii) the environment influence rediscovery, and (iii) human activities influence rediscovery.</p>
<p>For example, body mass (a species characteristic) may positively influence rediscovery, as larger lost species should be easier to find. Lost species occupying dense forests (a characteristic of the environment) may not be rediscovered as searching for them is difficult. Lost species affected by threats associated with human activities (e.g., invasive alien species, which are being spread to new locations by global trade) may not be rediscovered, as they may be extinct.</p>
<p>Based on these hypotheses, we collected data on a series of variables associated with each lost and rediscovered species (for example, their body mass), which we then analysed for their influence on rediscovery.</p>
<h2>Hard to find + neglected = rediscovered</h2>
<p>On the upside, our results suggest that while many lost species are difficult to find, with some effort and the use of new techniques, they are likely to be rediscovered. These species include those that are very small (including many lost reptile species), those that live underground, those that are nocturnal, and those living in areas that are difficult to survey.</p>
<p>In fact, since the completion of our study, <a href="https://www.theguardian.com/environment/2023/nov/30/back-from-the-brink-de-wintons-golden-mole-feared-extinct-rediscovered-after-86-years-aoe">De Winton’s Golden Mole</a> (<em>Cryptochloris wintoni</em>) has been rediscovered in South Africa. This species hadn’t been recorded in the wild since 1937. It lives underground much of the time, so searches were conducted using techniques including environmental DNA and thermal imaging.</p>
<p>Our results also suggest some species are neglected by conservation scientists, particularly those that are not considered to be charismatic, such as reptiles, small species and rodents. Searches for these species may also be rewarded with success. Voeltzkow’s chameleon (<em>Furcifer voeltzkowi</em>), a small reptile species, was <a href="https://www.livescience.com/lost-chameleon-rediscovered-after-century.html">rediscovered in Madagascar in 2018</a>.</p>
<h2>Lost or extinct?</h2>
<p>Unfortunately, our results also suggest that some lost species are unlikely to be found no matter how hard we look, because they are extinct. For example, remaining lost mammal species are, on average, three times larger than rediscovered mammal species. Some of these large, charismatic, conspicuous species should have been rediscovered by now.</p>
<p>Furthermore, one third of remaining lost mammal species are endemic to islands, where tetrapod species are <a href="https://www.sciencedirect.com/science/article/pii/S2351989421003978">particularly vulnerable to extinction</a>. The Bramble Cay melomys (<em>Melomys rubicola</em>), which was once considered to be a lost species, has recently been <a href="https://www.dcceew.gov.au/environment/biodiversity/threatened/nominations/comment/bramble-cay-melomys-2018">declared extinct</a> by the Australian Government. It occupied a small island that has been extensively surveyed – if it still existed it should have been rediscovered by now.</p>
<p>Lost bird species have, on average, been missing for longer than those that have been rediscovered (28% have been missing for more than 100 years), and many have been searched for on several occasions – perhaps some of these species should also have been rediscovered by now.</p>
<p>Nevertheless, unexpected rediscoveries of long-lost species like the <a href="https://www.edgeofexistence.org/species/cebu-flowerpecker/">Cebu flowerpecker</a> (<em>Dicaeum quadricolor</em>) do occur, so we shouldn’t lose hope, and we should definitely keep searching. However, some searches are being carried out for long-lost species that are considered to be extinct, such as the <a href="https://www.sciencedirect.com/science/article/pii/S0048969723014948">thylacine</a> (<em>Thylacinus cynocephalus</em>). Perhaps the limited resources available for biodiversity conservation would be better used to search for lost species likely to still exist.</p>
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<p><em>The author’s former MSc student, Tim Lindken, contributed to writing this article.</em></p><img src="https://counter.theconversation.com/content/220719/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Thomas Evans received funding from The Alexander von Humboldt Foundation.</span></em></p>There are hundreds of lost tetrapod species across the globe and their number are increasing decade-on-decade. This study aims to find out why some are rediscovered, while others are not.Thomas Evans, Research scientist, Freie Universität Berlin, Université Paris-SaclayLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2125012023-09-19T14:47:51Z2023-09-19T14:47:51ZWhy invasive ants are a silent threat to our ecosystems<figure><img src="https://images.theconversation.com/files/548832/original/file-20230918-27-85srij.jpg?ixlib=rb-1.1.0&rect=0%2C13%2C3113%2C2316&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The yellow crazy ant (Anoplolepis gracilipes) is a notorious invasive ant species.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/yellow-crazy-ant-anoplolepis-gracilipes-1960533274">Lukman_M/Shutterstock</a></span></figcaption></figure><p>Invertebrates are often described by <a href="https://faculty.washington.edu/timbillo/Readings%20and%20documents/ABRIDGED%20READINGS%20for%20PERU/Wilson_1987_Little_things_that_run.pdf">experts</a> as the “little things that run the world”, and ants are certainly one of the top contenders for this role. Ants help ecosystems to function normally and the <a href="https://www.pnas.org/doi/full/10.1073/pnas.2201550119">total weight</a> of all ants on Earth is roughly equivalent to 1.4 billion people, or 33 Empire State Buildings. </p>
<p>Unfortunately, some ants have become invasive species – organisms transported to a new ecosystem that cause damage. These introductions typically happen accidentally by people but can have dire consequences, as my team’s <a href="https://resjournals.onlinelibrary.wiley.com/doi/10.1111/icad.12672">new research</a> shows. </p>
<p>Invasive species are thought to be the <a href="https://link.springer.com/article/10.1007/s10531-018-1595-x">second largest</a> threat to biodiversity after habitat destruction. They are a <a href="https://doi.org/10.1016/j.tree.2005.01.003">leading cause</a> of animal extinctions, potentially leading to species extinction and ecosystem failure. </p>
<p>The International Union for the Conservation of Nature includes <a href="https://portals.iucn.org/library/sites/library/files/documents/2000-126.pdf">five different ant species</a> on its list of 100 of the world’s worst invasive alien species. But while invasive ants have dramatically transformed some of the areas they have been able to invade, other areas appear to be far less affected, or even totally unaffected.</p>
<h2>How bad are invasive ants, really?</h2>
<p>My team’s <a href="https://resjournals.onlinelibrary.wiley.com/doi/10.1111/icad.12672">study</a> draws from research conducted around the world to provide a measure of how bad or good invasive ants are for biodiversity loss. The results show us that invasive ants are every bit as bad as we had assumed.</p>
<p>We extracted data from 46 different research articles that studied how animal communities reacted to invasive ants, and combined the results. We only selected research that was done in relatively “undisturbed” natural environments, free from intensive human activity. </p>
<p>These are areas that invasive ants have dispersed to from more degraded habitats or urban environments. This allows us to more confidently claim that any negative or positive effects on animal communities are because of invasive ants, rather than other invasive species or some form of human disturbance such as agriculture or deforestation.</p>
<p>Our results show that animal communities respond overwhelmingly negatively to invasive ants. We found there were on average 50% fewer individual animals and species in areas invaded by ants, which is a dramatic fall in biodiversity. It is also important to remember these results are averages and, therefore, invasive ants may spell doom for some animal communities above and beyond these numbers.</p>
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<img alt="A close up of an ant with a large head crawls along a mossy piece of bark." src="https://images.theconversation.com/files/548020/original/file-20230913-19-n2k3ar.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/548020/original/file-20230913-19-n2k3ar.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/548020/original/file-20230913-19-n2k3ar.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/548020/original/file-20230913-19-n2k3ar.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/548020/original/file-20230913-19-n2k3ar.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/548020/original/file-20230913-19-n2k3ar.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/548020/original/file-20230913-19-n2k3ar.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The <em>Pheidole megacephala</em> or big-headed ant.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/macro-image-bigheaded-ant-2215004569">Alen thien/Shutterstock</a></span>
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<p>We also found that certain animal types, such as birds, reptiles and beetles, reacted more strongly than others. Native ants were the most strongly affected group. </p>
<p>This makes sense because many native ants will not only be directly attacked by invasive ants but they will also need to compete with them for food and nest sites. This is also bad news because of the general importance of native ants to the wider ecosystem. </p>
<p>Other groups that were badly affected were birds, beetles, butterflies, moths and reptiles. </p>
<p>We also found that the number of individuals in one insect group – bugs such as scale insects, aphids and mealybugs – increased. This group forms “mutualisms” with ants, which is where each species has a net benefit. </p>
<p>These insects are sap-sucking and exude a sugary liquid called “honeydew”, which ants love. Ants will defend these insects from their predators and parasites in return for this sugary secretion, enabling their populations to mutually increase. In some cases, these mutualisms can facilitate invasion – and to disastrous effect. </p>
<h2>How can something so small cause such a big problem?</h2>
<p>Although ants are small relative to how people perceive the world, they are numerous and tend to interact with a wide range of other organisms. This means they may be able to influence the ecosystem from multiple angles of attack. Invasive ants probably actively hunt down other species but competition for food or space is also important. </p>
<p>Ultimately, we need more research that can tease apart how ants are interacting with other species when they invade a location. What do they eat? Who do they compete with for food? Which habitats do they prefer and why? These questions urgently need answers so we can understand, prioritise and optimise how to minimise the negative effects of invasive ants.</p>
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Read more:
<a href="https://theconversation.com/why-red-fire-ants-and-yellow-crazy-ants-have-given-themselves-a-green-light-to-invade-australia-208479">Why red fire ants and yellow crazy ants have given themselves a green light to invade Australia</a>
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<p>Overall, our research is worrying. The reduction in animal diversity may have severe consequences for ecosystem functioning and the long-term future of rare species. Although there are crucial considerations to mitigate or reverse these effects, the conservation implications are not straightforward. </p>
<p>Ant eradication regimes are logistically complex and financially expensive, for example, and more than half <a href="https://doi.org/10.1016/j.biocon.2016.03.036">fail</a>. Early detection technology, as well as control measures such as toxic baits, can help conservationists prevent or reverse the effects of invasive ants on our ecosystems.</p>
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<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p class="fine-print"><em><span>Maximillian Tercel receives funding from Natural Environment Research Council and Durrell Wildlife Conservation Trust.</span></em></p>Invasive ants are a major threat to biodiversity, according to a study.Maximillian Tercel, PhD Candidate in Entomology, Cardiff UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1476562020-10-07T19:10:21Z2020-10-07T19:10:21ZIt was growing rainforests, not humans, that killed off Southeast Asia’s giant hyenas and other megafauna<figure><img src="https://images.theconversation.com/files/362096/original/file-20201007-14-1ciu27.jpeg?ixlib=rb-1.1.0&rect=56%2C56%2C4159%2C3148&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Peter Schouten</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Thinking of Southeast Asia today may conjure up images of dense tropical rainforests teeming with iconic jungle animals such as orangutans, tigers and monkeys.</p>
<p>Perhaps less well known, but just as important to these ecosystems, are a host of other large-bodied creatures: the goat-like <a href="https://en.wikipedia.org/wiki/Serow">serows</a> and <a href="https://en.wikipedia.org/wiki/Goral">gorals</a>, <a href="https://www.wwf.org.uk/learn/wildlife/asian-rhinos">three species of Asian rhino</a> and the only species of <a href="https://en.wikipedia.org/wiki/Malayan_tapir">tapir</a> still living in the “Old World”.</p>
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<a href="https://images.theconversation.com/files/362098/original/file-20201007-16-10up6pm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A tapir sitting in a green forest." src="https://images.theconversation.com/files/362098/original/file-20201007-16-10up6pm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/362098/original/file-20201007-16-10up6pm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/362098/original/file-20201007-16-10up6pm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/362098/original/file-20201007-16-10up6pm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/362098/original/file-20201007-16-10up6pm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/362098/original/file-20201007-16-10up6pm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/362098/original/file-20201007-16-10up6pm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&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 endangered Malayan tapir is the largest of four widely-recognized tapir species and the only one native to Asia.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<p>Together, these creatures comprise Southeast Asia’s megafauna, second only to Africa’s in diversity. These two continental ecosystems are the last vestiges of a world largely lost – one where giants roamed the Earth. But what caused so many megafauna species to go extinct?</p>
<p>Several theories have suggested either humans, climate change, or both drove Southeast Asia’s megafauna to extinction. However, our newest research published today in <a href="https://www.nature.com/articles/s41586-020-2810-y">Nature</a> indicates it was actually the rise and fall of savannah environments that drove this extinction event.</p>
<h2>Southeast Asia’s megafauna extinctions</h2>
<p>Southeast Asia has lost many large mammal species over the Quaternary period, the past 2.6 million years. They included the world’s largest ever ape, <em><a href="https://en.wikipedia.org/wiki/Gigantopithecus">Gigantopithecus</a></em>, elephant-like creatures known as <a href="https://en.wikipedia.org/wiki/Stegodon">stegodons</a> and large water buffaloes.</p>
<p>These extinctions also include one of our closest relatives, <em>Homo erectus</em>, and two island offshoots of the human family tree – <em>Homo floresiensis</em> (the “Hobbit”) and <em>Homo luzonensis</em>. One final human species is also recorded in the genes of Southeast Asians today: the Denisovans, who were once <a href="https://cosmosmagazine.com/palaeontology/southeast-asia-was-crowded-long-before-we-turned-up/">likely widespread throughout the region</a>.</p>
<p>According to <a href="https://theconversation.com/new-analysis-finds-no-evidence-that-climate-wiped-out-australias-megafauna-53821">previous research</a>, the lead antagonist in the megafauna extinction story is humans. Some have suggested the arrival of people to new lands over the past 60,000 years or more – who then overhunted and altered this new habitat – is what led to the loss of giant mammals. </p>
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Read more:
<a href="https://theconversation.com/new-analysis-finds-no-evidence-that-climate-wiped-out-australias-megafauna-53821">New analysis finds no evidence that climate wiped out Australia's megafauna</a>
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<p>Others researchers have contended <a href="https://theconversation.com/humans-coexisted-with-three-tonne-marsupials-and-lizards-as-long-as-cars-in-ancient-australia-138534">changes in climate</a> resulted in the extinction of the megafauna. While others suggest a <a href="https://theconversation.com/did-people-or-climate-kill-off-the-megafauna-actually-it-was-both-127803">combination</a> of both human and climate influences. </p>
<h2>Toothy insights into past environments</h2>
<p>For our research, we examined environmental changes in Southeast Asia over the <a href="https://www.nationalgeographic.com/science/prehistoric-world/quaternary/">past 2.6 million years</a>, to determine how they may have impacted extinctions. </p>
<p>We analysed the <a href="https://www.futurelearn.com/courses/archaeology/0/steps/15267">stable isotopes</a> of the teeth of mammals found in the region today, as well as those from available published fossil records.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/meet-the-giant-wombat-relative-that-scratched-out-a-living-in-australia-25-million-years-ago-141296">Meet the giant wombat relative that scratched out a living in Australia 25 million years ago</a>
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</p>
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<p>Stable isotopes are the non-radioactive forms of many elements. Stable isotopes of carbon and oxygen preserved in mammal teeth record important information on what kinds of plants those animals ate, and how wet their environments were, respectively. </p>
<p>Stable carbon isotopes are particularly helpful in recording whether animals predominantly ate leaves and fruits in shaded forests, or grasses in more open settings. This insight lets us identify shifts in environments over time.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/362110/original/file-20201007-14-1ux7jsp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Ancient tooth fossils." src="https://images.theconversation.com/files/362110/original/file-20201007-14-1ux7jsp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/362110/original/file-20201007-14-1ux7jsp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=363&fit=crop&dpr=1 600w, https://images.theconversation.com/files/362110/original/file-20201007-14-1ux7jsp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=363&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/362110/original/file-20201007-14-1ux7jsp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=363&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/362110/original/file-20201007-14-1ux7jsp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=456&fit=crop&dpr=1 754w, https://images.theconversation.com/files/362110/original/file-20201007-14-1ux7jsp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=456&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/362110/original/file-20201007-14-1ux7jsp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=456&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">These fossil teeth from extinct Southeast Asian elephants are one example of the various teeth available in the fossil record.</span>
<span class="attribution"><span class="source">Julien Louys</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>The fluctuating presence of forests</h2>
<p>During the first 1.5 million years or so of the Pleistocene (the geological epoch that lasted from about 2,580,000 to 11,700 years ago), the northern parts of Southeast Asia were largely forest, while the southern parts were woodlands or grasslands. </p>
<p>Later, from about one million years ago, forests retreated everywhere in the region and grasslands dominated. Coincident with these changes, large forest-adapted animals including <em>Gigantopithecus</em> and a giant panda relative disappeared from Southeast Asia’s northern parts.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/362105/original/file-20201007-20-1wpzz47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Model recreation of Gigantopithecus blacki." src="https://images.theconversation.com/files/362105/original/file-20201007-20-1wpzz47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/362105/original/file-20201007-20-1wpzz47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=831&fit=crop&dpr=1 600w, https://images.theconversation.com/files/362105/original/file-20201007-20-1wpzz47.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=831&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/362105/original/file-20201007-20-1wpzz47.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=831&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/362105/original/file-20201007-20-1wpzz47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1045&fit=crop&dpr=1 754w, https://images.theconversation.com/files/362105/original/file-20201007-20-1wpzz47.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1045&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/362105/original/file-20201007-20-1wpzz47.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1045&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"><em>Gigantopithecus blacki</em> was a large extinct ape that lived during the Pleistocene in what is now Southern China. It’s believed to have gone extinct about 300,000 years ago.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/22077805@N07/5484933159/in/photostream/">Greg Williams/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>Later still, around 400,000 years ago, the Southeast Asian Sunda Shelf began to submerge and climate cycles changed. Because of this, forest conditions returned.</p>
<p>At the same time, grassland-adapted creatures that had filled the region, including giant hyenas, <a href="http://www.eartharchives.org/articles/stegodon-the-elephant-with-sideways-trunk/">stegodons</a>, <a href="https://www.britannica.com/animal/bovid">bovids</a> and <em>Homo erectus</em> began to disappear – and largely went extinct by the end of the Pleistocene. The remainder were driven into the rainforests. </p>
<p>By the last few tens of thousands of years, we see the first evidence of <a href="https://en.wikipedia.org/wiki/Stratification_(vegetation)">stratified</a>, closed-canopy rainforests in Southeast Asia. These have dominated the region for the past 20,000 years or so.</p>
<p>Rainforest-adapted species should have been advantaged by the return of the rainforests, but one interloper changed that. <em>Homo sapiens</em> appears to be the only species in our family tree that was able to successfully adapt to and exploit rainforest environments. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/old-teeth-from-a-rediscovered-cave-show-humans-were-in-indonesia-more-than-63-000-years-ago-82075">Old teeth from a rediscovered cave show humans were in Indonesia more than 63,000 years ago</a>
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<p>And although humans lived in Southeast Asian rainforests as early as 73,000 years ago, it was probably only <a href="https://advances.sciencemag.org/content/4/6/e1701422">in the last 10,000 years</a> that <em>Homo sapiens</em> began to fundamentally alter these habitats and exploit the mammals within. </p>
<h2>A vanishing world</h2>
<p>Southeast Asia continues to preserve some of the most critically endangered megafauna on the planet. </p>
<p>Megafauna grassland specialists were the greatest loss as a result of disappearing savannahs 400,000 years ago. Today, rainforest megafauna are also at great risk of extinction. </p>
<p>Luckily for us, our own species’ fortunes changed for the better with the emergence of typical Southeast Asian rainforests. But we’re now the very thing threatening to <a href="https://theconversation.com/guns-snares-and-bulldozers-new-map-reveals-hotspots-for-harm-to-wildlife-113361">destroy them forever</a>.</p><img src="https://counter.theconversation.com/content/147656/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Julien Louys receives funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Patrick Roberts receives funding from the Max Planck Society and the European Research Council.</span></em></p>Several theories have suggested either humans, climate change or both drove megafauna extinctions in Southeast Asia. Our newest work suggests otherwise.Julien Louys, ARC Future Fellow, Griffith UniversityPatrick Roberts, Research Group Leader, Max Planck Institute of GeoanthropologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1278032019-12-03T18:36:08Z2019-12-03T18:36:08ZDid people or climate kill off the megafauna? Actually, it was both<figure><img src="https://images.theconversation.com/files/304383/original/file-20191129-45248-1sspxz7.jpg?ixlib=rb-1.1.0&rect=4%2C9%2C1497%2C1116&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">When freshwater dried up, so did many megafauna species.</span> <span class="attribution"><a class="source" href="https://epicaustralia.org.au">Centre of Excellence for Australian Biodiversity and Heritage</a>, <span class="license">Author provided</span></span></figcaption></figure><p>Earth is now firmly in the grips of its sixth “mass extinction event”, and it’s mainly <a href="https://theconversation.com/radical-overhaul-needed-to-halt-earths-sixth-great-extinction-event-68221">our fault</a>. But the modern era is definitely not the first time humans have been implicated in the extinction of a wide range of species.</p>
<p>In fact, starting about 60,000 years ago, many of the world’s largest animals disappeared forever. These “<a href="https://australianmuseum.net.au/learn/australia-over-time/megafauna/">megafauna</a>” were first lost in <a href="http://sahultime.monash.edu.au/explore.html">Sahul</a>, the supercontinent formed by Australia and New Guinea during periods of low sea level. </p>
<p>The causes of these extinctions have been debated for decades. Possible culprits include <a href="https://theconversation.com/climate-change-wiped-out-australias-megafauna-13966">climate change</a>, <a href="https://theconversation.com/new-analysis-finds-no-evidence-that-climate-wiped-out-australias-megafauna-53821">hunting or habitat modification by the ancestors of Aboriginal people</a>, or a <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2015.2399">combination of the two</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-is-a-mass-extinction-and-are-we-in-one-now-122535">What is a 'mass extinction' and are we in one now?</a>
</strong>
</em>
</p>
<hr>
<p>The main way to investigate this question is to build timelines of major events: when species went extinct, when people arrived, and when the climate changed. This approach relies on using <a href="https://theconversation.com/new-analysis-finds-no-evidence-that-climate-wiped-out-australias-megafauna-53821">dated fossils from extinct species</a> to estimate when they went extinct, and archaeological evidence to determine <a href="https://theconversation.com/an-incredible-journey-the-first-people-to-arrive-in-australia-came-in-large-numbers-and-on-purpose-114074">when people arrived</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/an-incredible-journey-the-first-people-to-arrive-in-australia-came-in-large-numbers-and-on-purpose-114074">An incredible journey: the first people to arrive in Australia came in large numbers, and on purpose</a>
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</em>
</p>
<hr>
<p>Comparing these timelines allows us to deduce the likely windows of coexistence between megafauna and people.</p>
<p>We can also compare this window of coexistence to long-term models of climate variation, to see whether the extinctions coincided with or shortly followed abrupt climate shifts.</p>
<h2>Data drought</h2>
<p>One problem with this approach is the scarcity of reliable data due to the extreme rarity of a dead animal being fossilised, and the low probability of archaeological evidence being preserved in Australia’s harsh conditions.</p>
<p>This means many studies are restricted to making conclusions regarding drivers of extinction at the scale of single palaeontological sites or of specific archaeological sites. </p>
<p>Alternatively, timelines can be constructed by including evidence across large spatial scales, such as over the <a href="https://theconversation.com/new-analysis-finds-no-evidence-that-climate-wiped-out-australias-megafauna-53821">entire continent of Australia</a>. </p>
<p>Unfortunately, this “lumping” of the available evidence across many different sites disregards the variation in the relative contribution of different extinction drivers across the landscape.</p>
<h2>Mapping extinction</h2>
<p>In our <a href="https://www.nature.com/articles/s41467-019-13277-0">research published in Nature Communications</a>, we developed advanced mathematical tools to map the regional patterns of the timing of megafauna disappearances and the arrival of Aboriginal ancestors across south-eastern Australia. </p>
<p>Based on these new maps, we can now work out where humans and megafauna coexisted, and where they did not. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/304225/original/file-20191128-178078-mo80fk.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/304225/original/file-20191128-178078-mo80fk.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/304225/original/file-20191128-178078-mo80fk.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=653&fit=crop&dpr=1 600w, https://images.theconversation.com/files/304225/original/file-20191128-178078-mo80fk.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=653&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/304225/original/file-20191128-178078-mo80fk.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=653&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/304225/original/file-20191128-178078-mo80fk.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=821&fit=crop&dpr=1 754w, https://images.theconversation.com/files/304225/original/file-20191128-178078-mo80fk.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=821&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/304225/original/file-20191128-178078-mo80fk.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=821&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Areas of coexistence and non-coexistence between humans and megafauna.</span>
<span class="attribution"><span class="source">F. Saltré</span></span>
</figcaption>
</figure>
<p>It turns out humans coexisted with the megafauna over about 80% of south-eastern Sahul for up to 15,000 years, depending on the region in question. </p>
<p>In other regions such as Tasmania, there was no such coexistence. This rules out humans as a likely driver of megafauna extinction in those areas. </p>
<p>We then aligned these windows of coexistence and non-coexistence in each part of the landscape with several environmental measures derived from climate simulations over the past 120,000 years. This gave us an idea about which factors best explained the timing of megafauna extinction in each part of the landscape. </p>
<p>Despite a major effect on extinctions in areas where megafauna and people did not coexist, there was nothing at all to explain the timing of megafauna extinctions in places where megafauna and people coexisted. </p>
<p>This surprising result suggested that we had missed something important in our analyses.</p>
<h2>Connecting the dots</h2>
<p>The major flaw in our approach was to analyse each location independently of its surroundings. Our initial model had failed to take account of the fact that an extinction in one place can affect an extinction in another location nearby. </p>
<p>Once we changed our model to incorporate these effects, the real picture finally emerged. We found that megafauna extinctions in areas were they coexisted with humans were most likely caused by a combination of human pressure and access to water.</p>
<p>In the other 20% of the landscape, where humans and megafauna did not coexist, we found that extinctions likely occurred because of a lack of plants, driven by increasingly dry conditions. This doomed many plant-eating megafauna species to extinction. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/304380/original/file-20191129-45296-yb8dhl.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/304380/original/file-20191129-45296-yb8dhl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/304380/original/file-20191129-45296-yb8dhl.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/304380/original/file-20191129-45296-yb8dhl.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/304380/original/file-20191129-45296-yb8dhl.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/304380/original/file-20191129-45296-yb8dhl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=425&fit=crop&dpr=1 754w, https://images.theconversation.com/files/304380/original/file-20191129-45296-yb8dhl.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=425&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/304380/original/file-20191129-45296-yb8dhl.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=425&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Relative importance (in %) of variables best describing the timing (first row) and the directional gradient (second row) of megafauna extinction in areas of non-coexistence (first column) and coexistence (second column) of people and megafauna.</span>
<span class="attribution"><span class="source">F. Saltré</span></span>
</figcaption>
</figure>
<h2>Space is key</h2>
<p>This is the first evidence that tens of thousands of years ago, the combination of humans and climate change was already making species more likely to disappear. Yet this pattern was invisible if we ignored the interconnectedness of the various regions involved. </p>
<p>This might be just the beginning we need for a new, more nuanced treatment of environmental change in the deep past in other regions of the world.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/11-000-scientists-warn-climate-change-isnt-just-about-temperature-126261">11,000 scientists warn: climate change isn't just about temperature</a>
</strong>
</em>
</p>
<hr>
<p>More importantly, our results reinforce <a href="https://theconversation.com/11-000-scientists-warn-climate-change-isnt-just-about-temperature-126261">scientists’ stark warning</a> about the immediate future of our planet’s plants and wildlife. Given rising human pressures on the natural world, coupled with an unprecedented pace of global warming, modern species are facing similar ravages.</p><img src="https://counter.theconversation.com/content/127803/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Corey J. A. Bradshaw receives funding from the Australian Research Council.</span></em></p><p class="fine-print"><em><span>Frédérik Saltré and Katharina J. Peters do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A drying climate and the arrival of people together finished off Australia’s megafauna.Frédérik Saltré, Research Fellow in Ecology & Associate Investigator for the ARC Centre of Excellence for Australian Biodiversity and Heritage, Flinders UniversityCorey J. A. Bradshaw, Matthew Flinders Fellow in Global Ecology and Models Theme Leader for the ARC Centre of Excellence for Australian Biodiversity and Heritage, Flinders UniversityKatharina J. Peters, Postdoctoral Fellow, Flinders UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1238842019-10-20T13:24:28Z2019-10-20T13:24:28ZWe need to understand the culture of whales so we can save them<figure><img src="https://images.theconversation.com/files/297414/original/file-20191016-156314-1dqgh0s.jpg?ixlib=rb-1.1.0&rect=1832%2C952%2C4149%2C3026&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Pod of sperm whales swimming off the coast of Sao Miguel Azores</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>We often think of culture as solely human. We think of our music, our clothes, our food, our languages. However, culture stretches far beyond <em>Homo sapiens</em>. As evidence of the existence of culture in other animal groups emerges (from insects, rats, fish to land mammals, primates and dolphins), humans need to rethink what it means to have culture. We must accept that what we have long considered our own might be shared. </p>
<p>This is especially important because culture can have important implications for conservation. Understanding an animal’s culture might be the only way to save them. </p>
<p>As a PhD candidate studying culture in a non-human species, the sperm whale, I have had the chance to witness its implications. The more time I spend with whales and learning from them, the more I am convinced that acknowledging their culture is necessary to understand and protect them. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/297340/original/file-20191016-98648-11fovu.jpg?ixlib=rb-1.1.0&rect=45%2C121%2C5080%2C3254&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/297340/original/file-20191016-98648-11fovu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/297340/original/file-20191016-98648-11fovu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/297340/original/file-20191016-98648-11fovu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/297340/original/file-20191016-98648-11fovu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/297340/original/file-20191016-98648-11fovu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/297340/original/file-20191016-98648-11fovu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Two sperm whales diving together.</span>
<span class="attribution"><span class="source">Felicia Vachon</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>What is culture?</h2>
<p>While most people have a general idea of what culture is, defining it can prove difficult. Culture is pervasive and, at the same time, it can express itself in such small, almost non-perceptible ways. Biology defines culture as shared information (or behaviour) that you acquire socially from your peers. </p>
<p>The importance of culture has long been recognized in humans. It is how we successfully inhabited all <a href="https://askabiologist.asu.edu/explore/biomes">the biomes of our planet</a>. Culture dictates our social interactions; the spontaneity of fashion and music; the laws that govern our societies and civilizations; the causes of our wars; the reason why, right now, you are reading this article instead of foraging in the forest. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/297410/original/file-20191016-98666-1lndbnf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/297410/original/file-20191016-98666-1lndbnf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/297410/original/file-20191016-98666-1lndbnf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/297410/original/file-20191016-98666-1lndbnf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/297410/original/file-20191016-98666-1lndbnf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/297410/original/file-20191016-98666-1lndbnf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/297410/original/file-20191016-98666-1lndbnf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Sperm whales in Dominica, an island nation in the Caribbean.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Culture shapes every aspect of our lives and has allowed us to become the dominant species we are today. However, although humans might be the most cultural species, they are not the only cultural species.</p>
<p>Instead, culture — expressed in small and big ways — is found throughout the animal kingdom: <a href="https://doi.org/10.1006/jhev.1994.1020">chimpanzees in West Africa use tools to crack nuts</a>, <a href="https://www.jstor.org/stable/41148928">capuchin monkeys have group-specific social rituals</a>, <a href="https://doi.org/10.1098/rsbl.2012.0174">dolphins cooperate with fishermen to obtain food</a>, <a href="https://doi.org/10.1016/bs.asb.2015.01.001">songbirds</a> and <a href="https://doi.org/10.1073/pnas.1621072114">humpback whales have ever-changing songs</a>, <a href="https://www.doi.org/10.1126/science.aat0985">bighorn sheep follow cultural migratory routes</a>, <a href="https://doi.org/10.1038/335719a0">reef fishes have preferred mating sites</a>, <a href="https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002564">bumblebees learn from each other to solve complex puzzles</a>. </p>
<p>And this is only the very tip of the iceberg. Every year, more evidence emerges on to the presence of culture in animals. </p>
<h2>The culture of whales</h2>
<p>Beyond primates, the animal group for which we have the most evidence of culture are the cetaceans (whales and dolphins). Among them, the sperm whale has received particular attention.</p>
<p>Like us, sperm whales have families, <a href="https://doi.org/10.1016/j.anbehav.2015.01.008">they have strong affiliations with a few individuals</a> and they are extremely social. Such a social environment is the <a href="https://doi.org/10.1038/ncomms9091">perfect substrate for culture</a>.</p>
<p>Sperm whales are matrilineal, which means that females stay with their mothers, forming groups called social units. These social units are comprised of one or two families and are stable over their entire lives. They travel together, socialize together, forage together and learn from each other. Beyond social units, sperm whale societies are also organized at a higher tier called vocal clans. Vocal clans include thousands of individuals and can be recognized acoustically. </p>
<p>Whales from different vocal clans sound incredibly different! </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/297411/original/file-20191016-98644-1ue329j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/297411/original/file-20191016-98644-1ue329j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/297411/original/file-20191016-98644-1ue329j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/297411/original/file-20191016-98644-1ue329j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/297411/original/file-20191016-98644-1ue329j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/297411/original/file-20191016-98644-1ue329j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/297411/original/file-20191016-98644-1ue329j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Sperm whale fluke.</span>
<span class="attribution"><span class="source">Felicia Vachon</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The most exciting part, however, is that individuals from different vocal clans not only have extremely different repertoires but also do not associate with each other, even if they live in the same environment. For example, in the Eastern Caribbean where I study sperm whales, we know about <a href="https://doi.org/10.1098/rsos.160061">two vocal clans: EC1 and EC2</a>. These two vocal clans have been identified in the same area (around the island of Dominica) but have never been seen interacting with each other: not even once in the 15 years the <a href="http://www.thespermwhaleproject.org/#home">Dominica Sperm Whale Project</a> has been studying the population. </p>
<p>In contrast, social units that belong to the same vocal clans are regularly observed foraging and socializing together. </p>
<p>Why is that? They live in the same environment, so surely, these differences are not the result of geographic adaptations. Could it be genetics? <a href="https://doi.org/10.1007/s10519-011-9513-y">The evidence says otherwise</a>: genetics can’t explain the variation in vocal repertoire. The only remaining explanation is culture. Perhaps whales actively choose to avoid whales from different vocal clans. They learn a specific vocal repertoire from their mothers and then only associate with individuals that share that same repertoire. </p>
<p><audio preload="metadata" controls="controls" data-duration="30" data-image="" data-title="EC1 vocal clan audio clip" data-size="859776" data-source="" data-source-url="" data-license="" data-license-url="">
<source src="https://cdn.theconversation.com/audio/1758/ec1-audio.mp3" type="audio/mpeg">
</audio>
<div class="audio-player-caption">
EC1 vocal clan audio clip.
</div></p>
<p><audio preload="metadata" controls="controls" data-duration="35" data-image="" data-title="EC2 vocal clan audio clip" data-size="1005696" data-source="" data-source-url="" data-license="" data-license-url="">
<source src="https://cdn.theconversation.com/audio/1759/ec2-audio.mp3" type="audio/mpeg">
</audio>
<div class="audio-player-caption">
EC2 vocal clan audio clip.
</div></p>
<p>These short audio clips are from the two vocal clans present in the Caribbean: EC1 and EC2. While EC1 whales often make clicks in the pattern click-click—-click-click-click, EC2 whales often make clicks in the pattern click-click-click-click-click. These patterns have the same number of clicks, but different tempos.</p>
<h2>The controversy</h2>
<p><a href="https://doi.org/10.3758/LB.38.3.329">Culture has important implications for conservation</a>. If a population is subdivided into cultural groups, then conservation efforts targeting only one group will lead to a loss of diversity. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/297412/original/file-20191016-98670-1p7r7fs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/297412/original/file-20191016-98670-1p7r7fs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/297412/original/file-20191016-98670-1p7r7fs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/297412/original/file-20191016-98670-1p7r7fs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/297412/original/file-20191016-98670-1p7r7fs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/297412/original/file-20191016-98670-1p7r7fs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/297412/original/file-20191016-98670-1p7r7fs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Young sperm whale breaching.</span>
<span class="attribution"><span class="source">Felicia Vachon</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>If cultural knowledge is mostly obtained from older matriarchs, then protecting these individuals at all costs should be our priority. If species are able to learn socially, they might respond differently to anthropogenic stressors. And yet, we seldom hear about it.</p>
<p>Acknowledging the presence of culture in other species would go against our anthropocentric view of the world: a world where humans are at the “end” of the evolutionary tree, smarter, more advanced and more important than other species. </p>
<p>It would blur the line between “us” and “them.” Once this occurs, how could we justify putting these cultural beings in cages, treating them as legal “property” and destroying their habitats? Perhaps it is time to re-think culture and acknowledge that other species might share what we long considered our own. </p>
<p>[ <em>You’re smart and curious about the world. So are The Conversation’s authors and editors.</em> <a href="https://theconversation.com/ca/newsletters?utm_source=TCCA&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=youresmart">You can read us daily by subscribing to our newsletter</a>. ]</p><img src="https://counter.theconversation.com/content/123884/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Felicia Vachon 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>Do animals have their own culture? A researcher studying the culture of whales argues that they do. She says understanding that may be one way to save them from extinction.Felicia Vachon, PhD candidate in the Department of Biology, Dalhousie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1017732018-08-22T10:37:09Z2018-08-22T10:37:09ZWhat makes some species more likely to go extinct?<figure><img src="https://images.theconversation.com/files/232772/original/file-20180820-30587-1060no3.jpg?ixlib=rb-1.1.0&rect=209%2C0%2C2286%2C1497&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Dinosaurs had some bad luck, but sooner or later extinction comes for all of us.</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/jSGBfrmEQnQ">rawpixel/Unsplash.com</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Though they say “‘tis impossible to be sure of <a href="http://freakonomics.com/2011/02/17/quotes-uncovered-death-and-taxes/">anything but death and taxes</a>,” a bit of financial chicanery may get you out of paying the taxman. But no amount of trickery will stop the inevitability of death. Death is the inescapable endpoint of life.</p>
<p>And this is as true for species as it is for individuals. Estimates suggest <a href="https://doi.org/10.1006/jtbi.1997.0508">99.99 percent of all species that have ever lived are now extinct</a>. All species that exist today – including human beings – will invariably go extinct at some point. </p>
<p><a href="https://scholar.google.com/citations?user=1u3axhQAAAAJ&hl=en&oi=ao">Paleontologists like me</a> know there are key moments in Earth’s history when extinction rates are high. For example, researchers have identified the <a href="https://doi.org/10.1038/nature09678">Big Five mass extinctions</a>: the five times over the past half billion years or so when more than three-quarters of the planet’s species have gone extinct in short order. Unfortunately, we are also now getting a good firsthand view of what extinction looks like, with the <a href="http://www.iucnredlist.org">rapid increase in extinction rates</a> over the last century.</p>
<p>But what factors make any one species more or less vulnerable to extinction? The <a href="https://www.elsevier.com/books/evolution-and-extinction-rate-controls/boucot/978-0-444-41182-2">rate of extinction varies</a> between different groups of animals and over time, so clearly not all species are equally susceptible. Scientists have done a great job of documenting extinction, but determining the processes that cause extinction has proved a bit more difficult. </p>
<h2>Who’s more vulnerable to extinction?</h2>
<p>Looking at modern examples, some tipping points that lead to the extinction of a species become obvious. <a href="https://doi.org/10.1098/rstb.2011.0015">Reduced population sizes is one such factor</a>. As the number of individuals of a species dwindles, it can lead to reduced genetic diversity and greater susceptibility to random catastrophic events. If the remaining population of a species is small enough, a single forest fire or even random variations in sex ratios <a href="https://www.scientificamerican.com/article/the-role-of-random-events/">could ultimately lead to extinction</a>. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/232787/original/file-20180820-30584-15rhcc8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/232787/original/file-20180820-30584-15rhcc8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/232787/original/file-20180820-30584-15rhcc8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/232787/original/file-20180820-30584-15rhcc8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/232787/original/file-20180820-30584-15rhcc8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/232787/original/file-20180820-30584-15rhcc8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/232787/original/file-20180820-30584-15rhcc8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/232787/original/file-20180820-30584-15rhcc8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">You won’t see another passenger pigeon.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/passenger-pigeon-wild-ectopistes-migratorius-188656403">Panaiotidi/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>Extinctions that have occurred in the recent past receive a great deal of attention – for example, <a href="https://doi.org/10.1080/08912960802376199">the dodo</a>, <a href="https://theconversation.com/friday-essay-on-the-trail-of-the-london-thylacines-91473">thylacine</a> or <a href="https://news.nationalgeographic.com/news/2014/08/140831-passenger-pigeon-martha-deextinction-dna-animals-species/">passenger pigeon</a>. But the vast majority of extinctions happened well before the appearance of humans. The fossil record is thus the primary source of data on extinction.</p>
<p>When paleontologists consider fossils in the context of what we know about past environments, a clearer picture of what causes the extinction of species starts to emerge. To date, the likelihood of extinction of a species has been linked to a host of factors.</p>
<p>We certainly know that changes in temperature are one important element. Almost every major rise or fall in global temperatures in Earth history has resulted in the <a href="https://doi.org/10.1098/rspb.2007.1302">extinction of a swath of different organisms</a>.</p>
<p>The <a href="https://doi.org/10.1111/geb.12333">size of the geographic area a species occupies</a> is also crucial. Species that are broadly distributed are less likely to go extinct than those that occupy a small area or whose habitat is disjointed.</p>
<p>There are also random phenomena that cause extinction. The meteorite responsible for the extinction of about 75 percent of life at the end of the <a href="https://www.livescience.com/29231-cretaceous-period.html">Cretaceous Period</a>, including the non-avian dinosaurs, is perhaps the <a href="https://doi.org/10.1098/rstb.1994.0045">best example of this</a>. This random aspect to extinction is why some have argued that <a href="https://archive.nytimes.com/www.nytimes.com/books/97/11/09/home/gould-shale.html?_r=1">“survival of the luckiest” may be a better metaphor</a> for the history of life than “survival of the fittest.”</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/232779/original/file-20180820-30590-1ubepp8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/232779/original/file-20180820-30590-1ubepp8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/232779/original/file-20180820-30590-1ubepp8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=275&fit=crop&dpr=1 600w, https://images.theconversation.com/files/232779/original/file-20180820-30590-1ubepp8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=275&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/232779/original/file-20180820-30590-1ubepp8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=275&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/232779/original/file-20180820-30590-1ubepp8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=346&fit=crop&dpr=1 754w, https://images.theconversation.com/files/232779/original/file-20180820-30590-1ubepp8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=346&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/232779/original/file-20180820-30590-1ubepp8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=346&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Studying extinct mollusks’ fossils suggested physiological reasons one species might be more likely to disappear.</span>
<span class="attribution"><a class="source" href="http://neogeneatlas.net/species/anadara-aequalitas/">Hendricks, J. R., Stigall, A. L., and Lieberman, B. S. 2015. The Digital Atlas of Ancient Life: delivering information on paleontology and biogeography via the web. Palaeontologia Electronica, Article 18.2.3E</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>Most recently, my colleagues and I identified a <a href="https://doi.org/10.1098/rspb.2018.1292">physiological component to extinction</a>. We found that the representative <a href="https://doi.org/10.1086/515881">metabolic rate</a> for both fossil and living mollusk species strongly predicts the likelihood of extinction. Metabolic rate is defined as the average rate of energy uptake and allocation by individuals of that species. Mollusk species with higher metabolic rates are more likely to go extinct than those with lower rates. </p>
<p>Returning to the metaphor of “survival of the fittest/luckiest,” this result suggests that “survival of the laziest” may apply at times. Higher metabolic rates correlate with higher mortality rates for individuals in both <a href="https://doi.org/10.1152/physrev.00047.2006">mammals</a> and <a href="https://doi.org/10.1186/1471-2148-6-67">fruit flies</a>, so metabolism may represent an important control on mortality at multiple biological levels. Because metabolic rate is linked to a constellation of characteristics including growth rate, time to maturity, maximum life span and maximum population size, it seems likely that the nature of any or all of these traits play a role in how vulnerable a species is to extinction. </p>
<h2>Plenty more extinction unknowns</h2>
<p>As much as scientists know about extinction drivers, there’s still a lot we don’t know. </p>
<p>For instance, some proportion of species go extinct regardless of any major environmental or biological upheaval. This is called the <a href="https://doi.org/10.1126/science.231.4734.129">background extinction rate</a>. Because paleontologists tend to focus on mass extinctions, background extinction rates are poorly defined. How much, or how little, this rate fluctuates isn’t well-understood. And, in total, most extinctions probably fall into this category.</p>
<p>Another problem is determining how important changing biological interactions are in explaining extinction. For instance, extinction of a species may occur when the abundance of a predator or a competitor increases, or when a crucial prey species goes extinct. The fossil record, however, rarely captures this kind of information. </p>
<p>Even the number of species that have gone extinct can be an enigma. We know very little about the current or past biodiversity of microorganisms, such as <a href="https://en.wikipedia.org/wiki/Bacteria">bacteria</a> or <a href="https://en.wikipedia.org/wiki/Archaea">archaea</a>, let alone anything about patterns of extinction for these groups.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/232782/original/file-20180820-30605-o7bf21.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/232782/original/file-20180820-30605-o7bf21.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/232782/original/file-20180820-30605-o7bf21.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=472&fit=crop&dpr=1 600w, https://images.theconversation.com/files/232782/original/file-20180820-30605-o7bf21.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=472&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/232782/original/file-20180820-30605-o7bf21.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=472&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/232782/original/file-20180820-30605-o7bf21.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=593&fit=crop&dpr=1 754w, https://images.theconversation.com/files/232782/original/file-20180820-30605-o7bf21.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=593&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/232782/original/file-20180820-30605-o7bf21.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=593&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Many animals – including the Scimitar-horned Oryx – are currently extinct in the wild.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/33590535@N06/3439149421">Drew Avery</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Perhaps the biggest mistake we could make when it comes to assessing and explaining extinction would be to take a one-size-fits-all approach. The vulnerability of any one species to extinction varies over time, and different biological groups respond differently to environmental change. While major changes in global climate have led to extinction in some biological groups, the same events have ultimately <a href="https://cup.columbia.edu/book/late-paleoceneearly-eocene-biotic-and-climatic-events-in-the-marine-and-terrestrial-records/9780231102384">led to the appearance of many new species</a> in others.</p>
<p>So how vulnerable any one species is to extinction due to human activities or the associated climate change remains sometimes an open question. It is clear that the current rate of extinction is rising well above anything that could be called background level, and is on track to be <a href="https://doi.org/10.1073/pnas.1704949114">the Sixth Mass Extinction</a>. The question of how vulnerable any one species – including our own – may be to extinction is therefore one scientists want to answer quickly, if we’re to have any chance of conserving future biodiversity.</p><img src="https://counter.theconversation.com/content/101773/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Luke Strotz is affiliated with the University of Kansas and his work is partly funded by the National Science Foundation.</span></em></p>Death is inevitable for individuals and also for species. With help from the fossil record, paleontologists are piecing together what might make one creature more vulnerable than another.Luke Strotz, Post-doctoral Researcher in Invertebrate Paleontology, University of KansasLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/810612017-07-17T23:10:08Z2017-07-17T23:10:08ZHow changing your diet could save animals from extinction<figure><img src="https://images.theconversation.com/files/178513/original/file-20170717-6069-118ptx8.jpg?ixlib=rb-1.1.0&rect=0%2C5%2C3329%2C2562&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Nearly one-third of tropical animal species face extinction if humans do not curb our growing appetites for beef, pork and other land-intensive meats. The Panamanian golden frog bred by the Vancouver Aquarium in this 2014 file photo may be extinct in its natural habitat.</span> <span class="attribution"><a class="source" href="http://www.cpimages.com/fotoweb/cpimages_details.pop.fwx?position=4&archiveType=ImageFolder&sorting=ModifiedTimeAsc&search=golden%20and%20frog&fileId=7ED4E565C8CEED275AEAE4A023E6F0DBFE75CC55B6586039AFA3A4A9FE951D3F22B34ACC50499F0099000C676EF56B79FD8133928F397B4233BD2F0B4AD858FA1638DDC87EBA9DB8E94B0839D79C227DF75A92B14A2B5F1A1225BCBD55DF59F06EB5BD7C5D2616EF6A9A1C79CADDD85732C9D97DC19FAC898908539CF52E943D">(THE CANADIAN PRESS/Darryl Dyck)</a></span></figcaption></figure><p>Transforming large swaths of the tropics into farmland could render almost one-third of wildlife there extinct, new research suggests. </p>
<p>From the Amazon rain forests to the Zambezi floodplains, intensive <a href="https://www.nature.com/articles/s41559-017-0234-3.epdf?author_access_token=b6E1O0fG6Z2pt7i17O5LcdRgN0jAjWel9jnR3ZoTv0Pk8s5ohTQBT5s50rsawiGLYGm5dBnXDBv1BU9t-BbojU0HQHmSIi7-KmQMAcQb1FgkSHgkdZLVFDTFxUt1byLe-6By_qDh-GymAFfpKHOMSA%3D%3D">monoculture farming could have a severe adverse impact on wildlife</a> around the world. </p>
<p>Wildlife would disappear most dramatically in the remaining forests and grasslands of Latin America and Sub-Saharan Africa. The greatest species loss would occur in the Peruvian Amazon basin where as many as 317 species could vanish as a result of agricultural development. </p>
<p>As a doctoral researcher at Humboldt University Berlin, I studied human food consumption, land use and how they affect wildlife. Our research was published July 17 in Nature Ecology and Evolution.</p>
<p>While human population has doubled since 1970, the number of <a href="http://wwf.panda.org/about_our_earth/all_publications/lpr_2016/">birds, mammals, reptiles and amphibians have dropped by more than half</a>. At its root, this widespread environmental destruction is a result of our growth as a species and increasing food consumption to sustain ourselves.</p>
<p>Although climate change casts a shadow over future conservation efforts, farming is the <a href="https://www.nature.com/nature/journal/v546/n7656/full/nature22900.html">No. 1 threat to wildlife</a>. We have already <a href="http://onlinelibrary.wiley.com/doi/10.1890/070062/abstract">altered some 75 per cent of the ice-free land</a> on this planet. If we continue along our current course, <a href="http://www.pnas.org/content/108/50/20260">we will need to double our crop production</a> to feed a growing world population that demands more resource-intensive foods such as meat and dairy.</p>
<h2>Africa at risk</h2>
<p>Our research shows that Sub-Saharan Africa is particularly at risk of harmful agricultural development. This region is at the crossroads of economic, demographic and agricultural growth, and minimizing potential effects of agricultural change there is an urgent challenge.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/178522/original/file-20170717-6046-18tdj36.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/178522/original/file-20170717-6046-18tdj36.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/178522/original/file-20170717-6046-18tdj36.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=181&fit=crop&dpr=1 600w, https://images.theconversation.com/files/178522/original/file-20170717-6046-18tdj36.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=181&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/178522/original/file-20170717-6046-18tdj36.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=181&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/178522/original/file-20170717-6046-18tdj36.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=228&fit=crop&dpr=1 754w, https://images.theconversation.com/files/178522/original/file-20170717-6046-18tdj36.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=228&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/178522/original/file-20170717-6046-18tdj36.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=228&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 potential biodiversity loss due to agricultural expansion and intensification worldwide could be as high as 317 species in some locales (left), reaching 31 per cent of known vertebrate animals (right).</span>
<span class="attribution"><span class="source">(Laura Kehoe)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>This becomes more worrying when considering the percentage of land that is currently at risk (i.e. natural but arable) and not protected against future development. Four-fifths of the regions we identify at risk of farmland expansion in Sub-Saharan Africa are unprotected. This is less than half of the 43 per cent protected in Latin America.</p>
<p>Some may mistakenly believe that protecting land from farming is about preserving wildlife habitat while local people go hungry. But it’s not a binary choice. Instead, the goal is to ensure an ample supply of nutritious food while at the same time conserving the most biodiverse and unique places on Earth. This is possible if we try. Knowing in advance what areas are most at risk allows us to better plan for a more sustainable future.</p>
<p>Aside from protecting land, food can be grown at little to no cost to biodiversity. For example, small-holder agro-ecological farming, which uses diverse cropping techniques along with fewer chemical fertilizers and pesticides, can produce <a href="http://www.sciencedirect.com/science/article/pii/S0006320712000821">large quantities of nutritious food at little to no cost</a> to wildlife. </p>
<p>We need to increase awareness of agro-ecological farming methods and secure local people’s land-holder rights — a crucial step to preventing large foreign corporations from buying up land for monoculture farming. </p>
<p>Communities adopting agro-ecological techniques is a win-win solution that goes a long way towards sustainably feeding the world without pushing wildlife towards extinction.</p>
<h2>What can policy makers do?</h2>
<p>Current large-scale <a href="http://www.conservation.org/How/Pages/Hotspots.aspx">conservation schemes</a> are based on factors that include past habitat loss and the threatened status of species, but none include the potential for future land-use change. We need to do a better job of predicting future pressures on wildlife habitat, especially because timely conservation action is cheaper and more effective than trying to fix the damage caused by farming. Our research takes a step in this direction.</p>
<p>We also show which countries could do with more support for conservation initiatives to protect land and find ways to sustainably grow food. Suriname, Guyana and the Republic of the Congo are just a few examples, as well as a number of countries in Latin America and Sub-Saharan Africa that are at the centre of high agricultural growth, low conservation investment and very high numbers of species that could be lost due to agricultural development. </p>
<p>Since most agricultural demand comes from richer nations, those countries should provide education and support for sustainable farming methods and locally led conservation efforts. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/178526/original/file-20170717-27512-dd5mjm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/178526/original/file-20170717-27512-dd5mjm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/178526/original/file-20170717-27512-dd5mjm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=590&fit=crop&dpr=1 600w, https://images.theconversation.com/files/178526/original/file-20170717-27512-dd5mjm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=590&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/178526/original/file-20170717-27512-dd5mjm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=590&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/178526/original/file-20170717-27512-dd5mjm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=741&fit=crop&dpr=1 754w, https://images.theconversation.com/files/178526/original/file-20170717-27512-dd5mjm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=741&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/178526/original/file-20170717-27512-dd5mjm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=741&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Map shows countries at risk of high species loss from agricultural development (yellow, bear icon), rapid agricultural growth 2009 to 2013 (orange, tractor symbol), and differing levels of conservation spending. Red represents low spending, high growth, and high species loss. Purple shows high spending, high growth, and low species loss. Green is high spending, low growth, and high species loss. Low values for all three factors are in grey. White represents no data. Dollar figures per square kilometre.</span>
<span class="attribution"><span class="source">Laura Kehoe</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>What can you do?</h2>
<p>All of this raises the question: How can we eat well without harming wildlife? One simple step we can all take right now that would have a far greater impact than any other (aside from having fewer children): Cut out the grain-fed beef. </p>
<p>The inefficiency of feeding livestock grain to turn them into meals for humans makes a <a href="http://www.sciencedirect.com/science/article/pii/S0048969715303697">diet heavy in animals particularly harsh on the Earth’s</a> resources. For example, in the United States, it takes <a href="https://books.google.ca/books/about/Should_We_Eat_Meat_Evolution_and_Consequ.html">25 kilograms of grain to produce one kilogram of beef</a>. Pigs have a grain-to-meat-ratio of 9:1, and chickens are 3:1. </p>
<p>Imagine throwing away 25 plates of perfectly good food to get one plate of beef — the idea is absurd and would likely be news if done en masse. But that is precisely what we are all unknowingly doing by eating resource-intensive meat. Articles on food waste seem half-baked when keeping in mind the bizarre grain-to-meat ratio of many of our most popular meats. </p>
<p>There are ways in which farmers can raise livestock with little to no environmental damage, particularly when land is not overgrazed and trees remain on the landscape. Indeed, in some remote areas grazing cattle are a crucial source of food and nourishment. Unfortunately, the industrialized feedlot model that relies heavily on grain makes up the overwhelming majority of the meat in your supermarket. That is the kind of farming that our research investigates.</p>
<h2>Livestock and deforestation</h2>
<p>To make matters worse, the grain we feed animals is the leading driver of deforestation in the tropics. And it’s a hungry beast: our <a href="http://www.nature.com/nature/journal/v478/n7369/full/nature10452.html">cows, pigs, and poultry devour over one-third of all crops</a> we grow. Indeed, the grain we feed to animals in the U.S. alone <a href="http://news.cornell.edu/stories/1997/08/us-could-feed-800-million-people-grain-livestock-eat">could feed an additional 800 million people</a> if it were eaten by us directly — more than the number of <a href="http://www.worldhunger.org/2015-world-hunger-and-poverty-facts-and-statistics/">people currently living in hunger</a>. </p>
<p>Livestock quietly causes <a href="http://www.ucsusa.org/global-warming/stop-deforestation/whats-driving-deforestation#.WSsT8e1tnIU">10 times more deforestation</a> than the palm oil industry but seems to get about 10 times less media attention. While it’s certainly true that avoiding unsustainable palm oil is a good idea, avoiding eating animals that were raised on grain is an even more effective conservation tactic.</p>
<p>Feeding the world without damaging nature is one of the greatest challenges humanity faces. But with a little foresight, better land governance and some simple meal changes, many of the solutions are at arm’s length. </p>
<p>For wildlife’s sake, go forth and enjoy your veggie burgers.</p><img src="https://counter.theconversation.com/content/81061/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Laura Kehoe 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 much as one-third of animal species in the tropics could be eradicated if their habitats continue to be converted for monoculture farming. We can all do something to make a difference.Laura Kehoe, Researcher in Conservation Decision Science and Land Use, University of VictoriaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/773802017-05-17T17:26:57Z2017-05-17T17:26:57ZGiraffes are in trouble – the US Endangered Species Act can help<figure><img src="https://images.theconversation.com/files/169641/original/file-20170517-24341-oq6dor.jpg?ixlib=rb-1.1.0&rect=1101%2C93%2C4082%2C3018&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A little protection over here, please?</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Giraffe-Park/36c2043572634a94abc6159640462260/9/0">AP Photo/Harry Hamburg</a></span></figcaption></figure><p>On April 19 of this year, <a href="http://www.ifaw.org/united-states/news/us-endangered-species-act-protection-sought-giraffes">five major wildlife protection groups</a> petitioned the United States Fish and Wildlife Service to list the giraffe (<em>Giraffa camelopardalis</em>) as an endangered species. <a href="http://www.ifaw.org/sites/default/files/default/Giraffe_ESA_Petition_final.pdf">As the petition asserted</a>, “the giraffe has suffered a major reduction in population size across its range primarily due to habitat loss, commercial overutilization, and severe poaching, and such decline continues unabated.”</p>
<p>If the Fish and Wildlife Service agrees to list the giraffe, a set of legal tools will become available to protect this iconic species. But how would listing in the U.S. help this African mammal, whose population numbers in the wild have <a href="https://giraffeconservation.org/giraffe-species/">dipped below 100,000</a>? </p>
<h2>Extinction is forever</h2>
<p>While extinction can be a natural process, the current rate of extinction is anything but. Scientists estimate that at least 99 out of 100 species extinctions in the world today are <a href="https://doi.org/10.1126/sciadv.1400253">the result of human action</a>. Although people rarely intend to drive species into oblivion, as with the giraffe, they do so through the destruction of habitat, poaching and legal hunting. As the petition notes, “[g]iraffes once occupied much of the savanna and savanna woodlands of Africa…. [It] has undergone a 36 to 40 percent population decline over the past 30 years.”</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/169587/original/file-20170516-11945-1sifhl1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/169587/original/file-20170516-11945-1sifhl1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/169587/original/file-20170516-11945-1sifhl1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/169587/original/file-20170516-11945-1sifhl1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/169587/original/file-20170516-11945-1sifhl1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/169587/original/file-20170516-11945-1sifhl1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/169587/original/file-20170516-11945-1sifhl1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/169587/original/file-20170516-11945-1sifhl1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Now the only place you’ll see a passenger pigeon is stuffed in a museum.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/bensutherland/252246647">Ben Sutherland</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>More than a century ago, scientists began to notice the disappearance of once prominent species around the world. The <a href="http://www.audubon.org/magazine/may-june-2014/why-passenger-pigeon-went-extinct">American passenger pigeon</a>, the <a href="http://johnjames.audubon.org/last-carolina-parakeet">Carolina parakeet</a> and the <a href="http://johnjames.audubon.org/extinction-great-auk">Great Auk</a> – once well-established in North America – disappeared. Other species like the American bison and many kinds of whales had once played central roles in important ecosystems but had been reduced to small remnant populations.</p>
<p>The existence of species is important to people for many reasons. Sometimes species provide <a href="https://www.nwf.org/%7E/media/PDFs/Wildlife/medicinalbenefits9-06.ashx">clues for the development of medicines</a>. Often they play a fundamental role in <a href="http://edis.ifas.ufl.edu/pdffiles/UW/UW06400.pdf">maintaining the functioning of ecosystems</a> on which people depend. As Aldo Leopold – perhaps America’s most famous naturalist – <a href="https://global.oup.com/academic/product/round-river-9780195015638?cc=us&lang=en&#">noted</a>, </p>
<blockquote>
<p>“If the biota, in the course of aeons, has built something we like but do not understand, then who but a fool would discard seemingly useless parts? To keep every cog and wheel is the first precaution of intelligent tinkering.”</p>
</blockquote>
<p>What would you say to a child who saw a giraffe in a book and asked where giraffes lived? Would you be comfortable saying they’re all gone?</p>
<h2>Roots of regulation</h2>
<p>In 1964, the International Union for the Conservation of Nature (IUCN) <a href="http://www.iucnredlist.org/about/introduction">began tracking the conservation status of species</a> on its “<a href="http://www.iucnredlist.org">Red List</a>.” Although the IUCN provides information only about the status of species, this is the first step in helping to limit extinction because it allows conservation efforts to be directed where they’re most needed.</p>
<p>A few years later in the United States, the <a href="https://www.fws.gov/endangered/laws-policies/esa-history.html">federal government began keeping an official list</a> of species in danger of extinction – what we call endangered species – and species likely to become endangered within the foreseeable future – threatened species.</p>
<p>The <a href="https://www.fws.gov/endangered/laws-policies/esa.html">Endangered Species Act</a> (ESA), passed in 1973, goes further than just identifying imperiled species. Under its terms, listed species are protected from actions “authorized, funded or carried out” by the federal government that may jeopardize their continued existence or adversely affect their essential habitat. Species members are also protected from direct harm by any person. Commerce in species protected by the ESA is generally a crime.</p>
<p>The purpose of the ESA is the “conservation” of protected species. In practice, that means bringing the species back to the point where it no longer requires the protection of the ESA. The law’s goal is not to preserve tiny populations on the brink of extinction but to recover species populations that are resilient enough to survive the bad luck which is so often part of living on the planet.</p>
<p>Listing is the public, administrative process whereby a species can become entitled to protection under the Endangered Species Act. It centers around one question: Is this creature or plant in danger of extinction? At the listing stage, the federal government can consider only scientific evidence in making its decision. Anyone can initiate the listing process via petition.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/169642/original/file-20170517-24337-dqysh4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/169642/original/file-20170517-24337-dqysh4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/169642/original/file-20170517-24337-dqysh4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=396&fit=crop&dpr=1 600w, https://images.theconversation.com/files/169642/original/file-20170517-24337-dqysh4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=396&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/169642/original/file-20170517-24337-dqysh4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=396&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/169642/original/file-20170517-24337-dqysh4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=498&fit=crop&dpr=1 754w, https://images.theconversation.com/files/169642/original/file-20170517-24337-dqysh4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=498&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/169642/original/file-20170517-24337-dqysh4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=498&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 2016 ceremony for the delisting of the island fox, which federal officials announced had recovered enough under a dozen years of protection by the ESA to be reclassified.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Island-Fox/2c80cbf62cc8417784da38e59f20f172/1/0">AP Photo/Reed Saxon</a></span>
</figcaption>
</figure>
<p>Evidence suggests the ESA works. A recent report in the Endangered Species Bulletin noted that of the 78 species first listed under the federal precursor to the Endangered Species Act in 1967, <a href="https://www.fws.gov/endangered/news/episodes/bu-Spring2017/coverstory/index.html">only four have been officially declared extinct</a> after half a century. Many others, such as the California condor, the grizzly bear and <a href="https://www.fws.gov/endangered/news/episodes/bu-Spring2017/story3/">the whooping crane</a>, have seen remarkable <a href="https://www.fws.gov/Endangered/map/index.html">recovery progress</a>. Some, <a href="https://ecos.fws.gov/ecp0/profile/speciesProfile?spcode=B008">including the bald eagle</a>, have even been removed from the list.</p>
<p>There are now <a href="https://ecos.fws.gov/ecp0/reports/box-score-report">1,382 species of animals listed under the Endangered Species Act</a> as threatened or endangered; 711 live largely within the borders of the United States. For these species, the federal Endangered Species Act can help preserve habitat, require “consultation” on projects that need federal approval and make most hunting illegal.</p>
<h2>American listing for an African animal</h2>
<p>The giraffe, of course, is not native to the United States. How would ESA listing help it? The habitat destruction and overharvesting that threaten the giraffe aren’t happening within U.S. borders.</p>
<p>The answer lies in the role the United States plays in buying and selling giraffe parts. According to a U.S. Fish and Wildlife Service database, <a href="http://www.ifaw.org/sites/default/files/default/Giraffe_ESA_Petition_final.pdf#page=%5B8%5D">over the past decade Americans imported</a> more than 21,000 giraffe bone carvings, more than 3,000 skin pieces and 3,744 hunting trophies. If many people want giraffe parts, the demand can be too high for survival of the species. Heightened demand for giraffe products can encourage people to hunt illegally – for example, taking more giraffes than limits allow or hunting in places where it is not permitted.</p>
<p>An international treaty, the <a href="https://cites.org/">Convention on International Trade in Endangered Species of Wild Fauna and Flora</a> (1973), known by its acronym, CITES, also addresses this problem. Countries that are party to the treaty <a href="https://cites.org/sites/default/files/eng/disc/CITES-Convention-EN.pdf">meet periodically to list species</a> that are threatened due to international trade. The treaty has two appendices for listing species: Appendix I results in an almost complete ban on commercial international trade; Appendix II requires all international trade in that species be monitored and subject to permits. The giraffe is not currently listed on <a href="https://cites.org/eng/app/appendices.php">either of the CITES appendices</a>, but this does not prevent individual countries – such as the United States – from deciding to limit imports.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/169644/original/file-20170517-24313-1eskfq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/169644/original/file-20170517-24313-1eskfq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/169644/original/file-20170517-24313-1eskfq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=411&fit=crop&dpr=1 600w, https://images.theconversation.com/files/169644/original/file-20170517-24313-1eskfq4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=411&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/169644/original/file-20170517-24313-1eskfq4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=411&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/169644/original/file-20170517-24313-1eskfq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=517&fit=crop&dpr=1 754w, https://images.theconversation.com/files/169644/original/file-20170517-24313-1eskfq4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=517&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/169644/original/file-20170517-24313-1eskfq4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=517&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">For centuries, shark fin, usually served as soup, has been a coveted delicacy in Chinese cooking.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Shark-Finning/4f2a0db541834a4e9727f38d95773a5f/2/0">AP Photo/Kin Cheung, File</a></span>
</figcaption>
</figure>
<p>Around the world, markets for species parts are sometimes driven by traditional uses – things like carving ivory or using certain animal parts in traditional medicines. New uses fuel demand too; think of newly wealthy businessmen in Vietnam <a href="http://awsassets.panda.org/downloads/trafficrhinoreportsummary.pdf">consuming rhino horn</a> mixed with water or alcohol to show how rich they are. Sometimes, the two can converge: An increase in <a href="https://www.theguardian.com/science/blog/2016/mar/10/shark-fin-soup-a-dangerous-delicacy-for-humans-and-sharks-alike">consumption of shark fin soup</a> has been tied to a traditional celebration dish being served by more people as China’s middle class grew.</p>
<p>Listing on the ESA would require the federal government to limit imports of giraffe parts into the United States and would therefore help curtail global demand. The ESA cannot ensure habitat protection or require other countries to take affirmative conservation action to protect the giraffe. But listing in the U.S. would limit one important threat in which Americans do play a role.</p><img src="https://counter.theconversation.com/content/77380/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Annecoos Wiersema is a member of the Accountability Panel of the Wildlife Justice Commission and a member of the IUCN's World Commission on Environmental Law.</span></em></p><p class="fine-print"><em><span>Federico Cheever 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>Giraffe populations have declined by more than a third over the past 30 years. Two wildlife law experts explain the protections that would come with including them on a US list of endangered species.Federico Cheever, Professor of Environmental and Natural Resources Law, University of DenverAnnecoos Wiersema, Professor of International Law, University of DenverLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/607112016-06-08T15:58:08Z2016-06-08T15:58:08ZFossil teeth reveal the secret rise of mammals – millions of years before dinosaurs became extinct<figure><img src="https://images.theconversation.com/files/125700/original/image-20160608-3475-zhgazj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Early mammal _Purgatorius unio_</span> <span class="attribution"><span class="source">Nobu Tamura</span></span></figcaption></figure><p>What would have happened if an asteroid hadn’t killed the dinosaurs? Perhaps mammals wouldn’t have evolved to become the planet’s dominant group of animals and humans would never have existed. We’re certainly used to the idea that it was only after the dinosaurs (apart from birds) became extinct around 66m years ago, that mammals were able to develop and spread around the globe. But new research suggests this picture of Earth’s evolution may not be completely accurate.</p>
<p>Work by a team that includes me and other palaeontologists from the universities of Chicago and Southampton has unveiled a <a href="http://rspb.royalsocietypublishing.org/content/283/1832/20160256">new level of detail</a> of early mammals. We discovered that the therian mammals (the kind that gave rise to most modern mammals) were actually beginning to diversify between 10m years and 20m years before the Cretaceous mass extinction event that wiped out the dinosaurs.</p>
<p>This finding reflects the considerable changes in our understanding of the early evolution of mammals, thanks to exceptional fossils found over the last few years. </p>
<p>Previously, most palaeontologists thought that mammal diversity was suppressed by the <a href="https://www.ucl.ac.uk/news/news-articles/1215/221215-mammal-diversity">dominance of dinosaurs</a>. This was largely based on the fact that many of the early mammal fossils that had been found were from small, insect-eating animals with very similar feeding habits and life histories. But with the help of some astounding new fossils, including several from China, we have shown that mammals at this time were much more diverse than this suggests.</p>
<p>We focused on studying several aspects of early mammal diversity, including the number of species through time and how these animals differed in both their physical structure and the way they lived. We also looked at how these things changed through time, particularly during the period either side of the extinction event. To do this, we studied the shape of teeth of hundreds of early mammal specimens in museum fossil collections.</p>
<h2>Greater diversity</h2>
<p>Mammal teeth are highly developed, with uniquely complicated series of cusps, troughs and pits that perform precise functions for feeding. This means the specific shape of teeth can offer a wealth of information on the lives of long-extinct animals.</p>
<p>Tracking changes in tooth shape through time showed us that the mammals that lived during the years leading up to the dinosaurs’ demise had widely varied diets. This also helped us uncover another surprising finding. Mammals with the most extreme tooth shapes disappeared immediately following the extinction, which suggests that those that had the most specialised diets suffered along with the dinosaurs.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/125738/original/image-20160608-3516-15ev253.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/125738/original/image-20160608-3516-15ev253.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/125738/original/image-20160608-3516-15ev253.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/125738/original/image-20160608-3516-15ev253.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/125738/original/image-20160608-3516-15ev253.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/125738/original/image-20160608-3516-15ev253.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/125738/original/image-20160608-3516-15ev253.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Answers in the teeth.</span>
<span class="attribution"><span class="source">Dave Grossnickle</span></span>
</figcaption>
</figure>
<p>Our research follows <a href="http://www.pnas.org/content/113/18/5036.abstract">other recent findings</a> that dinosaur diversity was already decreasing before the extinction event, exactly as mammals were on the rise. So what caused this growing change in the prehistoric animal kingdom? One explanation is that the rapid spread of flowering plants (angiosperms) during the late Cretaceous period had a <a href="http://www.nature.com/nature/journal/v483/n7390/abs/nature10880.html">significant effect</a> on the ecology of animal groups.</p>
<p>It is possible that mammals may have been able to adapt to this change in plant life and flourish while the dinosaurs could not. Small-bodied mammals may have been early adaptors to the range of new food sources (fruit and seeds), ecosystems and insect prey provided by the flowering plants. Meanwhile, <a href="http://bit.ly/22SKTpA">non-avian dinosaurs</a> felt more of the negative effects as these flowering plants took over their habitats, causing their traditional food sources to disappear.</p>
<h2>Mammals’ shaky start</h2>
<p>Another traditional theory that our research questions is that mammals <a href="https://www.ucl.ac.uk/news/news-articles/1215/221215-mammal-diversity">diversified rapidly</a> immediately after the dinosaurs went extinct. Traditionally, the extinction has been seen as an ideal opportunity for mammal evolution to take off, but our findings suggest that early mammals were also hit by a <a href="http://rspb.royalsocietypublishing.org/content/283/1832/20160256">selective extinction event</a>. Some that could live off of a wide variety of foods were able to survive, but many other mammals with specialised diets went extinct.</p>
<p>By offering a more realistic image of the dynamics of mass extinction on mammals, our research may also provide important evidence of how mammals <a href="https://www.sciencedaily.com/releases/2014/01/140122134234.htm">could be affected</a> by man-made climate change. It raises the question of whether we should prepare for a similar selective extinction event in modern mammals as occurred 66m years ago.</p>
<p>This highlights how studying the fossils of long-dead organisms can actually help us to model our own effects on global ecosystems and habitats. In a rapidly changing world, the fossil record is a unique and unadulterated constant that may provide solutions far beyond what most people expect.</p><img src="https://counter.theconversation.com/content/60711/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Elis Newham receives funding from NERC, EPSRC. </span></em></p>New research reveals that mammals didn’t wait for the dinosaurs to die out before starting their rapid spread.Elis Newham, PhD candidate, University of SouthamptonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/597582016-05-23T16:26:20Z2016-05-23T16:26:20ZHow lessons from past extinctions can help save Madagascar’s lemurs<figure><img src="https://images.theconversation.com/files/123546/original/image-20160523-11012-ue2y70.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lemurs are some of the world’s most threatened animals</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>It is common knowledge that the world faces an historic threat to biodiversity and natural species everywhere. This threat, caused by climate change, loss of habitats and over-exploitation – among other things – may be new. But it is not unprecedented. Extinctions have occurred throughout geological history, some of them relatively recently. A lot can be learnt from these past events to help us prevent future extinctions. And scientists are doing just that.</p>
<p>One example comes from Madagascar, the African island that is home to the lemur. These emblematic species occur only in <a href="http://evolution.berkeley.edu/evolibrary/news/091001_madagascar">Madagascar</a>. They are of high conservation priority, and are also incredibly charismatic. In fact, <em>Time</em> magazine recently named them the new pop-culture star of the mammal <a href="http://time.com/45828/lemurs-sloths-popularity/">world</a>. They supplanted sloths, in case you were wondering. They are some of the world’s most threatened animals – more than <a href="http://www.iucnredlist.org/news/iucn-red-list-raises-more-red-flags-for-threatened-species">90%</a> of the roughly 100 species face extinction. They need all the pop-culture cachet they can get.</p>
<p>Lemurs are most threatened by the loss and fragmentation of their habitats, which are mainly tropical forests. In the past 60 years nearly half of Madagascar’s forest cover has been converted for agricultural production, mining and urban <a href="http://www.iucnredlist.org/news/iucn-red-list-raises-more-red-flags-for-threatened-species">development</a>. This trend continues today.</p>
<h2>Ghost stories</h2>
<p>The word lemur is derived from the Latin <em>lemures</em>, which refers to spirits of the dead – a bit portentous given their current state. The name reflects the Malagasy word for lemur, <em>gidro</em> or ghost. It’s named for the eerie calls sometimes wafting through forests at dawn and dusk.</p>
<p>As it happens, this ghostly name is already quite fitting. Madagascar experienced a massive extinction event between 2,000 and 500 years ago that saw the disappearance of at least <a href="https://today.duke.edu/2014/12/giantlemurs">17 species of lemur</a>. Scientists debate the extent of human involvement in these extinctions, but it is well accepted that we played a major <a href="http://www.karger.com/Article/Pdf/105152">role</a>. This time period coincides with an increase in human populations on the island, and activities like forest fragmentation and hunting certainly contributed to these extinctions.</p>
<p>But what was bad for Madagascar in the past may prove useful in the future. By investigating the cascading effects of historical lemur extinctions on their forest habitats, we can make informed estimates about the effects of lemur loss in the present. This can help shape conservation and management decisions for the future.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/123547/original/image-20160523-10986-5ijj8n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/123547/original/image-20160523-10986-5ijj8n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/123547/original/image-20160523-10986-5ijj8n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/123547/original/image-20160523-10986-5ijj8n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/123547/original/image-20160523-10986-5ijj8n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/123547/original/image-20160523-10986-5ijj8n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/123547/original/image-20160523-10986-5ijj8n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/123547/original/image-20160523-10986-5ijj8n.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">Half of Madagascar’s forest cover has been converted for other purposes and this has had a massive impact on lemurs.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Spreading seeds</h2>
<p>Lemurs rely on forest habitats for food and shelter, but they also play key roles in maintaining the health of the forests in which they live. The same was also true of now-extinct lemurs. For example, when lemurs eat the fruit of a tree – let’s say a species of palm tree – they can swallow seeds and eventually deposit them, in their faeces, in new growing sites. </p>
<p>Seed dispersal to new growing sites helps plants to establish new populations and this is incredibly important for maintaining healthy and diverse forests. In Madagascar, lemurs are especially important seed dispersers, as there are very few fruit-eating birds in comparison with tropical forests elsewhere. Protecting fruit-eating lemurs will benefit the forest ecosystems in which they live by promoting seed dispersal, and the establishment of new and diverse plant generations. And part of that will be investigating how past extinctions affected seed dispersal in Madagascar’s forests.</p>
<p>Scientists can infer the diet and potential seed-dispersal abilities of extinct lemur species using chemical analyses, and dental and cranial morphology. Many of the recently extinct lemur species ate fruit, and all of them were substantially larger than any lemur living today.</p>
<p>It turns out that losing these large animals created many orphaned trees, or tree species with seeds too big to be swallowed and dispersed by the remaining, smaller, fruit-eating lemurs found today. In the absence of their lemur dispersers, these tree species may still persist due to their long life-spans, and other uncertain dispersal mechanisms such as wind and rats. But their populations are likely in decline, and their futures in jeopardy.</p>
<p>Today the critically endangered <a href="http://www.iucnredlist.org/details/22918/0">black-and-white</a> ruffed lemur is the largest living seed disperser in Madagascar. Many forest trees have seeds that are too large to be eaten by any living species besides this <a href="http://www.pnas.org/content/113/18/5041.abstract">lemur</a>. This foreshadows the echoed effects of extinction, and highlights the precarious balance between living lemurs and the ecosystems in which they function.</p>
<h2>Lessons from the past</h2>
<p>We can gain new perspectives for future conservation plans by understanding how the ghosts of lemurs past are still affecting ecosystems today. It’s important to make plans that account for these delicate inter-species relationships, as well as ones that involve local communities and incentivise alternative land-use practices to deforestation. </p>
<p>Many reserves and conservation organisations – <a href="http://www.worldwildlife.org/places/madagascar">the World Wildlife Fund</a>, <a href="http://www.madagascarfaunaflora.org">Madagascar Flora and Fauna Group</a>, and <a href="http://campuspress.yale.edu/bezamahafaly/">Bezà Mahafaly</a>, to name a few – are already adopting more integrative conservation strategies. Maybe, by taking a more holistic approach, we can prevent ourselves from fulfilling the prophesy of such an ephemeral name.</p><img src="https://counter.theconversation.com/content/59758/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sarah Federman receives funding from the NSF as a graduate student research fellow. She is affiliated with Yale University as a doctoral candidate. </span></em></p>More than 90% of Madagascar’s lemurs face extinction. Losing them will mean a loss of the valuable function they serve to the forests in which they live.Sarah Federman, PhD student studying evolutionary mechanisms underlying spatial patterns in diversity, Yale UniversityLicensed as Creative Commons – attribution, no derivatives.