tag:theconversation.com,2011:/global/topics/vultures-18259/articlesVultures – The Conversation2023-11-16T19:03:39Ztag:theconversation.com,2011:article/2163582023-11-16T19:03:39Z2023-11-16T19:03:39ZGiant eagles and scavenging vultures shared the skies of ancient Australia<figure><img src="https://images.theconversation.com/files/555992/original/file-20231026-21-xbm5tb.jpg?ixlib=rb-1.1.0&rect=11%2C0%2C7507%2C3686&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A flock of vultures (_Cryptogyps lacertosus_) and Australian ravens watch and wait (left), as an adult eagle _Dynatoaetus pachyosteus_ feeds on the carcass of a dead _Diprotodon_ (centre), while a younger bird seeks to join in. In the nearby treetops, a second adult _D. pachyosteus_ feeds its hungry chick (right).</span> <span class="attribution"><span class="source">John Barrie</span></span></figcaption></figure><p>Today, Australia is home to 17 species of hawks and eagles. But the fossil record shows some other, rather special raptors were present in the relatively recent past. </p>
<p>Tens of thousands of years ago, Australia was home to species such as <a href="https://theconversation.com/australias-extinct-giant-eagle-was-big-enough-to-snatch-koalas-from-trees-200341"><em>Dynatoaetus gaffae</em>, the largest eagle ever to have lived in Australia</a>, and <a href="https://theconversation.com/it-was-long-thought-these-fossils-came-from-an-eagle-turns-out-they-belong-to-the-only-known-vulture-species-from-australia-187017"><em>Cryptogyps lacertosus</em>, our only known vulture</a>. </p>
<p>Now, we have discovered another ancient eagle shared the skies with these prehistoric predators. In a <a href="https://doi.org/10.1080/03115518.2023.2268780">new paper in the journal Alcheringa</a>, we describe the formidable <em>Dynatoaetus pachyosteus</em>, based on fossils found in the Naracoorte Caves in South Australia.</p>
<h2>A new eagle unearthed</h2>
<p><em>Dynatoaetus pachyosteus</em> (the name means “powerful eagle with thick bones”) lived during the Pleistocene (a time period spanning from 2.5 million to 11,700 years ago). It had a wingspan similar to that of a wedge-tailed eagle, but with much more robust and powerful wings and legs. It was slightly smaller than its cousin, the massive <em>Dynatoaetus gaffae</em>. </p>
<p>This formidable predator would most likely have preyed on medium to large marsupials and birds. It may even have attacked juveniles and weakened individuals of huge megafaunal species like the <a href="https://theconversation.com/fossil-find-reveals-giant-prehistoric-thunder-birds-were-riddled-with-bone-disease-173745">giant flightless bird</a> <em>Genyornis</em>.</p>
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<a href="https://images.theconversation.com/files/556402/original/file-20231028-30-aal6zi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An illustration of an eagle feeding a chick, together with photos of four bones." src="https://images.theconversation.com/files/556402/original/file-20231028-30-aal6zi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/556402/original/file-20231028-30-aal6zi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/556402/original/file-20231028-30-aal6zi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/556402/original/file-20231028-30-aal6zi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/556402/original/file-20231028-30-aal6zi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/556402/original/file-20231028-30-aal6zi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/556402/original/file-20231028-30-aal6zi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The large extinct eagle <em>Dynatoaetus pachyosteus</em> (left) and comparison of its humerus or upper arm/wing bone (centre) to that of a modern female wedge-tailed eagle (right). Scale bar = 10mm.</span>
<span class="attribution"><span class="source">John Barrie (reconstruction) / Ellen Mather (photos)</span></span>
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<p><em>Dynatoaetus pachyosteus</em> shared the Pleistocene landscape with at least two other large eagles, the huge <em>Dynatoaetus gaffae</em> and the wedge-tailed eagle we know today. For these species to coexist, they would have likely needed to have slightly different ecological roles to avoid outright competition. </p>
<p>“Niche separation” typically occurs by <a href="https://www.nature.com/scitable/knowledge/library/resource-partitioning-and-why-it-matters-17362658/">exploiting different kinds of food or habitats</a>. These three eagles most likely coexisted by specialising in hunting different prey and nesting in different places.</p>
<p>The occurrence of both species of the <em>Dynatoaetus</em> genus in Australia (and nowhere else) has implications for the evolution of eagles. <em>Dynatoaetus gaffae</em> and <em>D. pachyosteus</em> presumably evolved from a common ancestor in Australia that diverged into two species, a process that typically takes a very long time. </p>
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Read more:
<a href="https://theconversation.com/australias-extinct-giant-eagle-was-big-enough-to-snatch-koalas-from-trees-200341">Australia's extinct giant eagle was big enough to snatch koalas from trees</a>
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<p>This suggests the ancestor of this genus was already ensconced on our continent millions of years before the two Pleistocene species arose. <em>Dynatoaetus pachyosteus</em> and <em>D. gaffae</em> together form a rare example of a raptor genus diversifying into multiple species entirely on the Australian continent (what scientists call “endemic evolutionary radiation”). </p>
<p>There are only two raptor genera today restricted to Australia, and both consist of only a single species: <em>Hamirostra</em> (the black-breasted buzzard) and <em>Lophoictinia</em> (the square-tailed kite).</p>
<h2>Primitive vultures of ancient Australia</h2>
<p>Our research has also revealed intriguing new information about another extinct raptor, the vulture <em>Cryptogyps lacertosus</em>. </p>
<p>Fossils from the Green Waterhole (also known as Fossil Cave), in the Tantanoola district near Mt Gambier, give us a more complete picture of this species. We found several paired wing bones, two shoulder bones, a vertebra and a toe bone, all probably from a single individual. </p>
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Read more:
<a href="https://theconversation.com/it-was-long-thought-these-fossils-came-from-an-eagle-turns-out-they-belong-to-the-only-known-vulture-species-from-australia-187017">It was long thought these fossils came from an eagle. Turns out they belong to the only known vulture species from Australia</a>
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<p>The additional bones of <em>Cryptogyps</em> indicate it was a rather primitive vulture, less adapted for the long periods of soaring flight characteristic of modern vultures.</p>
<p>Thanks to the sediment around the fossils, we also have a very precise date of when <em>Cryptogyps</em> was alive. Many of the Green Waterhole fossils were buried in a deposit of calcite rafts – crystals that form on the surface of still bodies of water in caves. </p>
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<a href="https://images.theconversation.com/files/556401/original/file-20231028-24-5h6thl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Photos of several bones and an illustration of a vulture-like bird" src="https://images.theconversation.com/files/556401/original/file-20231028-24-5h6thl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/556401/original/file-20231028-24-5h6thl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=689&fit=crop&dpr=1 600w, https://images.theconversation.com/files/556401/original/file-20231028-24-5h6thl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=689&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/556401/original/file-20231028-24-5h6thl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=689&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/556401/original/file-20231028-24-5h6thl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=866&fit=crop&dpr=1 754w, https://images.theconversation.com/files/556401/original/file-20231028-24-5h6thl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=866&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/556401/original/file-20231028-24-5h6thl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=866&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">Fossil bones from the wing and shoulder of the extinct vulture <em>Cryptogyps lacertosus</em>, recovered from Green Waterhole, South Australia. Scale bar = 50mm. Life reconstruction top right.</span>
<span class="attribution"><span class="source">Ellen Mather (photos) / John Barrie (reconstruction)</span></span>
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<p>Today, most of the cave is submerged because of a high water table, but in the past, it was mostly dry. A pool of water deeper in the cave was where these calcite rafts formed. </p>
<p>The water was likely what attracted animals into the cave in the first place. These animals then died, and their bones sank to the bottom of the pool along with the calcite rafts. Our team dated these calcite rafts – and thus the entombed <em>Cryptogyps</em> fossils – at approximately 60,000 years old.</p>
<h2>Mammal extinctions affect birds of prey</h2>
<p>When we think of the <a href="https://theconversation.com/did-people-or-climate-kill-off-the-megafauna-actually-it-was-both-127803">mass extinction</a> of Australian megafauna, we tend to think about the demise of large mammals, such as the “giant wombat” <em>Diprotodon optatum</em>, the “marsupial lion” <em>Thylacoleo carnifex</em>, and the giant short-faced kangaroo <em>Procoptodon goliah</em>. Some large reptiles are also commonly recognised as victims: the giant goanna (Megalania) <em>Varanus priscus</em>, the constricting snake <em>Wonambi naracoortensis</em>, and <a href="https://theconversation.com/meet-the-biggest-and-most-bizarre-skink-ever-found-in-australia-it-became-extinct-47-000-years-ago-206764">even a giant armoured skink</a> <em>Tiliqua frangens</em>.</p>
<p>But as we can see from the case of our large eagles and vultures, other groups of animals were also affected. Birds of prey, especially large and scavenging species, <a href="https://www.semanticscholar.org/paper/The-Late-Pleistocene-Continental-Avian-extinction-Tyrberg/6cfc6bfea30c8b5635d5250eede1556c4d654402">went extinct around the world during the Late Pleistocene</a>, their food supply likely affected by the loss of large mammalian species. Australia appears to have been no exception to the rule.</p>
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<a href="https://images.theconversation.com/files/556394/original/file-20231028-27-4hz9e1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two photos of eagles in flight, one with a white belly and the other with dark, patterned wings." src="https://images.theconversation.com/files/556394/original/file-20231028-27-4hz9e1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/556394/original/file-20231028-27-4hz9e1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=379&fit=crop&dpr=1 600w, https://images.theconversation.com/files/556394/original/file-20231028-27-4hz9e1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=379&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/556394/original/file-20231028-27-4hz9e1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=379&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/556394/original/file-20231028-27-4hz9e1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=476&fit=crop&dpr=1 754w, https://images.theconversation.com/files/556394/original/file-20231028-27-4hz9e1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=476&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/556394/original/file-20231028-27-4hz9e1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=476&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 wedge-tailed eagle (<em>Aquila audax</em>) and the white-bellied sea eagle (<em>Icthyophaga leucogaster</em>) are the largest birds of prey found in modern Australia.</span>
<span class="attribution"><span class="source">Michael Lee</span></span>
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<p>The new fossils reveal many of Australia’s large birds of prey did not survive the megafaunal extinction event in the Late Pleistocene, roughly 50,000 years ago. The two largest species that managed to persist to the present are the wedge-tailed eagle, which is a generalist hunter found throughout the continent, and the white-bellied sea eagle, which targets fish and has a coastal distribution. </p>
<p>It is likely our three extinct large raptors – two giant eagles and a vulture – were too specialised as hunters and scavengers of megafauna to adapt to a rapidly changing world. Their extinction likely caused a further cascade of effects through the ecosytem: in Asia, for instance, more recent loss of vultures has led to increased populations of scavenging feral dogs and higher prevalance of <a href="https://www.sciencedaily.com/releases/2022/02/220214095744.htm">diseases such as rabies</a>.</p><img src="https://counter.theconversation.com/content/216358/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ellen K. Mather received funding from BirdLife Australia Raptor Group.</span></em></p><p class="fine-print"><em><span>Michael Lee receives funding from the Australian Research Council, Flinders University and the Royal Society of South Australia</span></em></p><p class="fine-print"><em><span>Trevor H. Worthy has received funding from The Australian Research Council for research on fossil birds. He has previously worked for Flinders University and now has an adjunct status there.</span></em></p>New fossils reveal Australia was once home to a much greater diversity of huge eagles and vultures, which died off alongside ‘giant wombats’ and ‘marsupial lions’.Ellen K. Mather, Adjunct Associate Lecturer in Palaeontology, Flinders UniversityMike Lee, Professor in Evolutionary Biology (jointly appointed with South Australian Museum), Flinders UniversityTrevor H. Worthy, Associate Professor, Vertebrate Palaeontology Group, Flinders UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1870172022-07-19T20:29:58Z2022-07-19T20:29:58ZIt was long thought these fossils came from an eagle. Turns out they belong to the only known vulture species from Australia<figure><img src="https://images.theconversation.com/files/474759/original/file-20220719-16-4osyy5.jpeg?ixlib=rb-1.1.0&rect=0%2C0%2C2991%2C1989&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The extinct species may have been a relative of the living Griffon Vulture (pictured). </span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>In 1905, a fragment of a fossil wing bone discovered near the Kalamurina Homestead, South Australia, was described as an extinct eagle and named <em>Taphaetus lacertosus</em>, meaning “powerful grave eagle”. </p>
<p>Now <a href="https://doi.org/10.11646/zootaxa.5168.1.1">research</a> published by myself and <a href="https://theconversation.com/profiles/trevor-h-worthy-172603">my</a><a href="https://theconversation.com/profiles/mike-lee-8293">colleagues</a> can reveal this species was no eagle at all. It was an “Old World” vulture, which we have renamed <em>Cryptogyps lacertosus</em>, or “powerful hidden vulture”.</p>
<p>This is the first time one of these scavenging raptors has been found to have lived in Australia. Living more than tens of thousands of years ago, we believe <em>Cryptogyps</em> likely died out with ancient Australia’s megafauna. There’s much about the species we’ve yet to find out.</p>
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<img alt="A woman in a lab with fossil bones" src="https://images.theconversation.com/files/474379/original/file-20220716-24-h5v98o.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/474379/original/file-20220716-24-h5v98o.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/474379/original/file-20220716-24-h5v98o.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/474379/original/file-20220716-24-h5v98o.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/474379/original/file-20220716-24-h5v98o.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/474379/original/file-20220716-24-h5v98o.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/474379/original/file-20220716-24-h5v98o.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">Here’s me at the Flinders University palaeontology lab, holding the fossil vulture tarsus (left) and a tarsus of a living vulture species (right).</span>
<span class="attribution"><span class="source">Author provided</span></span>
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<h2>A puzzling absence</h2>
<p>Vultures are birds of prey that feed almost exclusively on decaying flesh. They play a vital role in their ecosystems by speeding up the consumption of carcasses. In this way, they assist in redistributing nutrients, and help limit the spread of diseases. </p>
<p>They can be divided into two groups. “New World” vultures inhabit North and South America and belong to their own distinct family. “Old World” vultures are found in Africa, Europe and Asia, and belong to the same family as eagles and hawks.</p>
<p>Considering they’re so widespread today, it’s surprising vultures long appeared absent from Australia. It’s even stranger when you look at the fossil record across South-East Asia, where vulture fossils have been found as far south as the Indonesian island of Flores. Surely they could have flown a little further?</p>
<p>What’s more, the Australian environment would have been well-suited to support vultures until about 50,000 years ago. Back then, megafaunal marsupials were widespread and abundant across the continent, and would have provided plentiful carcasses for scavengers.</p>
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Read more:
<a href="https://theconversation.com/this-giant-kangaroo-once-roamed-new-guinea-descended-from-an-australian-ancestor-that-migrated-millions-of-years-ago-185778">This giant kangaroo once roamed New Guinea – descended from an Australian ancestor that migrated millions of years ago</a>
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<h2>The shape of a scavenger</h2>
<p>We aren’t the first to consider there might be vultures in Australia’s fossil record. Other palaeontologists have previously suggested some Australian bird fossils could belong to vultures, and the Kalamurina “eagle” was one such example.</p>
<p>My colleagues and I wanted to find out if this really was the case, and so we began comparing the fossil bones of <em>Cryptogyps</em> to a wide range of living birds of prey, including vultures.</p>
<p>Being scavengers, vultures have a very different musculature and bone structure to eagles. This fact proved to be crucial in confirming <em>Cryptogyps lacertosus</em> was indeed a vulture. </p>
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<img alt="Tarsi of Wedge-tailed eagle and fossil vulture" src="https://images.theconversation.com/files/474404/original/file-20220717-14-u3tkt6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/474404/original/file-20220717-14-u3tkt6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=783&fit=crop&dpr=1 600w, https://images.theconversation.com/files/474404/original/file-20220717-14-u3tkt6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=783&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/474404/original/file-20220717-14-u3tkt6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=783&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/474404/original/file-20220717-14-u3tkt6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=984&fit=crop&dpr=1 754w, https://images.theconversation.com/files/474404/original/file-20220717-14-u3tkt6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=984&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/474404/original/file-20220717-14-u3tkt6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=984&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">A silhouette size comparison of a Wedge-tailed Eagle (left) and <em>Cryptogyps lacertosus</em> (right), and tarsi comparisons of both below.</span>
<span class="attribution"><span class="source">Ellen Mather, Wedge-tailed Eagle silhoutette derived from photo by Vicki Nunn.</span></span>
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<p>The material used in our research included the original wing bone from the Kalamurina Homestead, two identical wing bone fragments from the Wellington Caves in New South Wales, and two “tarsi” (lower leg bones) – one from Wellington Caves and the other from Leaena’s Breath Cave in Western Australia. All of these bones are thought to belong to <em>Cryptogyps</em>.</p>
<p>Close examination of the bones, and comparison to eagles and vultures from around the world revealed their muscle scars and structure are more vulture-like than eagle-like, especially for the tarsi. This strongly indicates they belonged to a scavenger.</p>
<p>To further test this, we placed the fossils in an evolutionary tree with other birds of prey. Our results confirmed what the comparison suggested: <em>Cryptogyps</em> was indeed a vulture, and potentially a close relative of the Griffon Vulture found across Europe and Asia.</p>
<h2>The life and death of a species</h2>
<p>Based on the leg bones, we can infer <em>Cryptogyps</em> didn’t actively hunt and grab prey with powerful talons. Rather, it would have scavenged dead animals as vultures do now. </p>
<p>At this point in time, we don’t have enough of the skeleton to know exactly what <em>Cryptogyps lacertosus</em> looked like, or what it ate.</p>
<p>It could have been a social species, gathering in large flocks around the corpses of megafauna such as <em>Diprotodon</em> or <em>Protemnodon</em>. Or perhaps it was a solitary bird, searching and feeding alone, or in pairs. It may have fed on the soft insides of the body, or may have preferred the tougher muscle and skin.</p>
<p>Gaining this information will require more discoveries in the future. What isn’t in question, however, is that like all vultures today <em>Cryptogyps lacertosus</em> would have played an important role in ecosystem health.</p>
<p>Fossils of <em>Cryptogyps</em> are believed to date from the Middle to Late Pleistocene, somewhere between 770,000 and 40,000 years ago. Its extinction was very likely related to the demise of Australia’s megafauna around 60,000–40,000 years ago.</p>
<p>As large-bodied animals died off, the supply of carcasses scavengers need to survive would have dwindled significantly. Starvation would have become common, breeding attempts less successful and eventually the total population would have fallen below the threshold needed to survive. </p>
<p>Other more generalist raptors such as Wedge-tailed Eagles and Black Kites subsequently filled the reduced scavenging niche.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/474757/original/file-20220719-91509-9h3rmq.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Camera is zoomed in on the top half of a Wedge-tailed Eagle" src="https://images.theconversation.com/files/474757/original/file-20220719-91509-9h3rmq.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/474757/original/file-20220719-91509-9h3rmq.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/474757/original/file-20220719-91509-9h3rmq.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/474757/original/file-20220719-91509-9h3rmq.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/474757/original/file-20220719-91509-9h3rmq.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/474757/original/file-20220719-91509-9h3rmq.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/474757/original/file-20220719-91509-9h3rmq.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Wedge-tailed Eagle is the largest bird of prey in Australia today.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Australia has the sobering distinction of being the only continent to lose its vultures entirely. Sadly, around half of all living vultures today are endangered and under threat of extinction. </p>
<p>And the <a href="https://education.nationalgeographic.org/resource/role-scavengers-carcass-crunching">consequences</a> of <a href="https://www.sciencedaily.com/releases/2016/05/160505145035.htm">this decline</a> have been dire, including increased disease transmission in both animal and human populations, potential impacts on the nutrient cycle, and the restructuring of ecosystems. </p>
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Read more:
<a href="https://theconversation.com/the-endangered-condor-surprised-researchers-by-producing-fatherless-chicks-could-virgin-birth-rescue-the-species-170965">The endangered condor surprised researchers by producing fatherless chicks. Could 'virgin birth' rescue the species?</a>
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<img src="https://counter.theconversation.com/content/187017/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ellen K. Mather does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The identification of a vulture that lived more than 50,000 years ago is shedding more light on biodiversity loss and ecosystem change in Australia.Ellen K. Mather, Adjunct associate lecturer, Flinders UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1709652021-11-04T05:21:21Z2021-11-04T05:21:21ZThe endangered condor surprised researchers by producing fatherless chicks. Could ‘virgin birth’ rescue the species?<figure><img src="https://images.theconversation.com/files/430146/original/file-20211104-24-1oafxjd.jpeg?ixlib=rb-1.1.0&rect=85%2C54%2C5090%2C3391&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Virgin birth – which involves the development of an unfertilised egg – has preoccupied humans for aeons. And although it can’t <a href="http://theconversation.com/is-virgin-birth-possible-yes-unless-you-are-a-mammal-52379">happen in mammals</a>, it does seem to be possible in other animals with backbones (vertebrates), such as birds and lizards. </p>
<p>A <a href="https://academic.oup.com/jhered/advance-article/doi/10.1093/jhered/esab052/6412509">recent paper</a> led by researchers from San Diego Zoo in the United States reports two fatherless male chicks raised in a program to save the Californian condor from extinction. Could the species be restored by a single surviving female?</p>
<p>Sexual reproduction is fundamental in all vertebrates. Normally it requires an egg from a female to be fertilised by a sperm from a male, so each parent contributes one copy of the genome. </p>
<p>Violation of this rule, as for the fatherless condor chicks, tells us a lot about why sexual reproduction is such a good biological strategy – as well as how sex works in all animals, including humans.</p>
<h2>How the fatherless chicks were identified</h2>
<p>The magnificent California condor, a type of vulture, is the largest flying bird in North America. In 1982 the species declined to a population of just <a href="https://academic.oup.com/jhered/advance-article/doi/10.1093/jhered/esab052/6412509">22 individuals</a>, sparking an ambitious captive breeding program led by San Diego Zoo which has seen numbers start to grow.</p>
<p>With so few birds, the team had to be careful not to choose parents that were closely related, as a lack of genetic variation would produce less vigorous offspring and steepen the slide to extinction. </p>
<p>The researchers conducted a detailed genetic study of the birds to avoid this, using DNA markers that were specific for condors and which varied between individual birds. They collected feathers, blood and eggshells from nearly 1,000 birds over 30 years. </p>
<p>By analysing these data, they established parentage, confirming that half the DNA markers in each chick came from a female and half from a male, as you’d expect. They continued to follow the fates of hundreds of captive-bred chicks in the colony, and after releasing them into the wild.</p>
<p>But there was something unusual about two male chicks, as detailed in the recent paper. These chicks, which hatched several years apart from eggs laid by different females, had DNA markers that all came from the female parent. There was no trace of markers from the male she’d been paired with. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/430151/original/file-20211104-27-h9x77u.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A condor chick" src="https://images.theconversation.com/files/430151/original/file-20211104-27-h9x77u.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430151/original/file-20211104-27-h9x77u.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430151/original/file-20211104-27-h9x77u.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430151/original/file-20211104-27-h9x77u.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430151/original/file-20211104-27-h9x77u.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430151/original/file-20211104-27-h9x77u.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430151/original/file-20211104-27-h9x77u.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">There are currently about 500 living condors in the world.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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</figure>
<h2>Virgin birth</h2>
<p>The development of unfertilised eggs is called “parthenogenesis” (from Greek words that literally mean “virgin creation”). It’s quite common in <a href="https://www.nationalgeographic.com/animals/article/parthenogenesis-how-animals-have-virgin-births">insects and other invertebrates</a> like aphids and starfish, and can be accomplished by several different mechanisms. But it’s very <a href="https://pubmed.ncbi.nlm.nih.gov/29559496/">rare in vertebrates</a>.</p>
<p>There have been reports of parthenogenesis in fish and reptiles that were housed without males. In Tennessee, a lonely female Komodo dragon held in captivity for many years gave up on finding a mate and <a href="https://www.scientificamerican.com/article/strange-but-true-komodo-d/">produced three viable</a> offspring on her own. So did a <a href="https://www.nationalgeographic.com/animals/article/141023-virgin-birth-pythons-snakes-animals-science">female python and a boa</a>, although these parthenogenic offspring all died early.</p>
<p>Some lizards, however, have adopted parthenogenesis as a way of life. There are <a href="https://www.scientificamerican.com/article/asexual-lizards/">female-only species</a> in Australia and the US in which females lay eggs carrying only combinations of their own genes.</p>
<p>Parthenogenesis also happens in domesticated chickens and turkeys raised in the absence of a male, but the embryo usually dies. There are only a few reports of fatherless male turkeys that made it to adulthood, and just one or two that produced sperm.</p>
<h2>How does it happen?</h2>
<p>In birds, parthenogenisis always results from an egg cell carrying a single copy of the genome (haploid). Eggs are made in the ovary of a female by a special sort of cell division called meiosis, which shuffles up the genome and also halves the chromosome number. Sperm cells are made by the same process in the testis of a male.</p>
<p>Normally an egg cell and a sperm cell fuse (fertilisation), incorporating both parents genomes and restoring the usual (diploid) number of chromosomes. </p>
<p>But in parthenogenesis, the egg cell is not fertilised. Instead, it achieves a diploid state either by fusing with another cell from the same division — which is normally jettisoned — or by replicating its genome without the cell being divided.</p>
<p>So rather than getting one genome from the mother and a different one from the father, the resulting egg only has a subset of the mother’s genes in a double dose. </p>
<h2>Fatherless birds will always be male</h2>
<p>Condors, like other birds, determine sex by Z and W sex chromosomes. These work in the opposite way to the human XX (female) and XY (male) system, in which the SRY gene on the Y chromosome <a href="http://theconversation.com/what-makes-you-a-man-or-a-woman-geneticist-jenny-graves-explains-102983">determines maleness</a>.</p>
<p>However, in birds males are ZZ and females are ZW. Sex is determined by the dosage of a gene (DMRT1) on the Z chromosome. The ZZ combination has two copies of the DMRT1 gene and makes a male, whereas the ZW combination has only one copy and makes a female. </p>
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<p>
<em>
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Read more:
<a href="https://theconversation.com/how-birds-become-male-or-female-and-occasionally-both-112061">How birds become male or female, and occasionally both</a>
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<p>Haploid egg cells receive either a Z or a W from the ZW mother. Their diploid derivatives will therefore be ZZ (normal male) or WW (dead). The reason WW embryos can’t develop is because the W chromosome contains hardly any genes, whereas the Z chromosome has 900 genes which are vital for development.</p>
<p>Fatherless chicks must therefore be ZZ males, as was observed.</p>
<h2>Why virgin birth fails</h2>
<p>Is it possible an endangered bird species such as the condor could be resuscitated from a lone female survivor, by hatching a fatherless male chick and breeding with it? </p>
<p>Well not quite. It turns out parthenogens (fatherless animals) don’t do so well. Neither of the two fatherless condors produced offspring of their own. One died before reaching sexual maturity and the other was weak and submissive – making it a poor prospect for fatherhood. </p>
<p>In chickens and turkeys, parthenogenesis produces either dead embryos or weak hatchlings. Even female-only lizard species, though they seem robust, are generally the product of a recent blending of two species which messed up meiosis and left them no other option. These species don’t seem to last long.</p>
<p>Why do parthenogens do so poorly? The answer goes to the core of a fundamental biological question. That is: why do we have sex at all? You’d think it would be more efficient for the mother’s genome to be simply handed down to her clonal offspring without bothering about meiosis.</p>
<h2>Variation is key</h2>
<p>But the evidence says it’s not healthy to have a genome consisting entirely of the mother’s genes. Genetic variation is all-important in the health of an individual and its species. Mixing the gene variants from male and female parents is vital.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/these-sex-starved-creatures-scavenge-new-genes-from-other-pondlife-56913">These sex-starved creatures scavenge new genes from other pondlife</a>
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<p>In diploid offspring with two parental genomes, good variants can cover for mutants. Individuals that inherit genes only from the mother may have two copies of a maternal mutant gene that weakens them – without a healthy version from a male parent to compensate.</p>
<p>Variation also helps protect populations from deadly viruses, bacteria and parasites. Meiosis and fertilisation provide many rearrangements of different gene variants, which can baffle pathogens. Without this added protection, pathogens could run amok in a population of clones, and a genetically similar population would not contain resistant animals.</p>
<p>So the ability of condor females to hatch chicks without a father is unlikely to save the species. On the bright side, human efforts have now led to hundreds of females – and males – flying the Californian skies.</p><img src="https://counter.theconversation.com/content/170965/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jenny Graves receives funding from the Australian Research Council</span></em></p>Researchers were surprised to find two female condors had managed to hatch chicks that had no fathers. But virgin birth does not seem to produce healthy birds that could strengthen the population.Jenny Graves, Distinguished Professor of Genetics and Vice Chancellor's Fellow, La Trobe UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1487722020-10-27T21:12:37Z2020-10-27T21:12:37ZGiant ‘toothed’ birds flew over Antarctica 40 million to 50 million years ago<figure><img src="https://images.theconversation.com/files/365550/original/file-20201026-21-t2z6hk.png?ixlib=rb-1.1.0&rect=9%2C14%2C3249%2C2013&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fossil remains indicate these birds had a wingspan of over 20 feet.</span> <span class="attribution"><span class="source">Brian Choo</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>Picture Antarctica today and what comes to mind? Large ice floes bobbing in the Southern Ocean? Maybe a remote outpost populated with scientists from around the world? Or perhaps colonies of penguins puttering amid vast open tracts of snow?</p>
<p>Fossils from Seymour Island, just off the Antarctic Peninsula, are painting a very different picture of what Antarctica looked like 40 to 50 million years ago – a time when the ecosystem was lusher and more diverse. Fossils of <a href="https://doi.org/10.1038/s41598-020-61973-5">frogs</a> and <a href="https://doi.org/10.1080/03115518.2011.565214">plants</a> such as ferns and conifers indicate Seymour Island was much warmer and less icy, while fossil remains from <a href="https://doi.org/10.7717/peerj.8268">marsupials and distant relatives of armadillos and anteaters</a> hint at the previous connections between Antarctica and other continents in the Southern Hemisphere.</p>
<p>There were also birds. Penguins were present then, as they are now, but fossil relatives of <a href="http://dx.doi.org/10.13679/j.advps.2019.0014">ducks, falcons and albatrosses</a> have also been found in Antarctica. My <a href="https://scholar.google.com/citations?user=5CGShQUAAAAJ&hl=en&oi=ao">colleagues</a> and <a href="https://scholar.google.com/citations?user=XlyfD9QAAAAJ&hl=en&oi=ao">I</a> published an <a href="https://doi.org/10.1038/s41598-020-75248-6">article in 2020</a> revealing new information about the fossil group that would have dwarfed all the other birds on Seymour Island: the pelagornithids, or “bony-toothed” birds. </p>
<h2>Giants of the sky</h2>
<p>As their name suggests, these ancient birds had sharp, bony spikes protruding from sawlike jaws. Resembling teeth, these spikes would have helped them catch squid or fish. We also studied another remarkable feature of the pelagornithids – their imposing size.</p>
<p>The largest flying bird alive today is the <a href="https://www.nationalgeographic.com/animals/birds/group/albatrosses/">wandering albatross</a>, which has a wingspan that reaches 11 ½ feet. The Antarctic pelagornithids fossils we studied have a wingspan nearly double that – about 21 feet across. If you tipped a two-story building on its side, that’s about 20 feet.</p>
<p>Across Earth’s history, very few groups of vertebrates have achieved powered flight – and only two reached truly giant sizes: birds and a group of <a href="https://www.amnh.org/exhibitions/pterosaurs-flight-in-the-age-of-dinosaurs/what-is-a-pterosaur">reptiles called pterosaurs</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/365561/original/file-20201026-23-p2l76b.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A model of an enormous prehistoric bird is mounted outdoor in the middle of a river. The wingspan reaches from bank to bank." src="https://images.theconversation.com/files/365561/original/file-20201026-23-p2l76b.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/365561/original/file-20201026-23-p2l76b.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/365561/original/file-20201026-23-p2l76b.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/365561/original/file-20201026-23-p2l76b.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/365561/original/file-20201026-23-p2l76b.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/365561/original/file-20201026-23-p2l76b.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/365561/original/file-20201026-23-p2l76b.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Full-size model of a Quetzalcoatlus on display at JuraPark in Baltow, Poland.</span>
<span class="attribution"><a class="source" href="https://upload.wikimedia.org/wikipedia/commons/5/5c/Kecalkoatl_%28Quetzalcoatlus%29_-_Baltow_%281%29.JPG">Aneta Leszkiewicz/Wikimedia</a></span>
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<p>Pterosaurs ruled the skies during the Mesozoic Era (252 million to 66 million years ago), the same period that dinosaurs roamed the planet, and they reached hard-to-believe dimensions. <a href="https://www.wired.com/2013/11/absurd-creature-of-the-week-quetz/">Quetzalcoatlus</a> stood 16 feet tall and had a colossal 33-foot wingspan.</p>
<h2>Birds get their opportunity</h2>
<p>Birds originated while dinosaurs and pterosaurs were still roaming the planet. But when an <a href="https://www.smithsonianmag.com/science-nature/dinosaur-killing-asteroid-impact-chicxulub-crater-timeline-destruction-180973075/">asteroid struck the Yucatan Peninsula 66 million years ago</a>, dinosaurs and pterosaurs both perished. Some <a href="https://www.audubon.org/news/how-birds-survived-asteroid-impact-wiped-out-dinosaurs">select birds survived</a>, though. These survivors diversified into the thousands of bird species alive today. Pelagornithids evolved in the period right after dinosaur and pterosaur extinction, when competition for food was lessened. </p>
<p><a href="https://doi.org/10.1002/spp2.1284">The earliest pelagornithid remains</a>, recovered from 62-million-year-old sediments in New Zealand, were about the size of modern gulls. The first giant pelagornithids, the ones in our study, <a href="https://doi.org/10.1038/s41598-020-75248-6">took flight over Antarctica about 10 million years later</a>, in a period called the Eocene Epoch (56 million to 33.9 million years ago). In addition to these specimens, fossilized remains from other pelagornithids have been found on every continent. </p>
<p>Pelagornithids lasted for about 60 million years before going extinct just before the Pleistocene Epoch (2.5 million to 11,700 years ago). No one knows exactly why, though, because few fossil records have been recovered from the period at the end of their reign. Some paleontologists cite <a href="https://doi.org/10.1080/02724634.2011.562268">climate change as a possible factor</a>.</p>
<h2>Piecing it together</h2>
<p>The fossils we studied are fragments of whole bones collected by paleontologists from the University of California at Riverside in the 1980s. In 2003, the specimens were transferred to Berkeley, where they now reside in the <a href="https://ucmp.berkeley.edu/">University of California Museum of Paleontology</a>. </p>
<p>There isn’t enough material from Antarctica to rebuild an entire skeleton, but by comparing the fossil fragments with similar elements from more complete individuals, we were able to assess their size. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/365552/original/file-20201026-17-1koc1h3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Photo of a fossil fragment of a jawbone section that has worn toothlike projections. Line drawing around it illustrates where in the jaw it would have fit." src="https://images.theconversation.com/files/365552/original/file-20201026-17-1koc1h3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/365552/original/file-20201026-17-1koc1h3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=573&fit=crop&dpr=1 600w, https://images.theconversation.com/files/365552/original/file-20201026-17-1koc1h3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=573&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/365552/original/file-20201026-17-1koc1h3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=573&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/365552/original/file-20201026-17-1koc1h3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=720&fit=crop&dpr=1 754w, https://images.theconversation.com/files/365552/original/file-20201026-17-1koc1h3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=720&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/365552/original/file-20201026-17-1koc1h3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=720&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">In life, the pelagornithid would have had numerous ‘teeth,’ making it a formidable predator.</span>
<span class="attribution"><span class="source">Peter Kloess</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>We estimate the pelagornithid’s skull would have been about 2 feet long. A fragment of one bird’s lower jaw preserves some of the “pseudoteeth” that would have each measured up to an inch tall. The spacing of those “teeth” and other measurements of the jaw show this fragment came from an individual as big as, if not bigger than, the largest known pelagornithids. </p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p>
<p>Further evidence of the size of these Antarctic birds comes from a second pelagornithid fossil, from a different location on Seymour Island. A section of a foot bone, called a tarsometatarsus, is the largest specimen known for the entire extinct group. </p>
<p>These pelagornithid fossil findings emphasize the importance of natural history collections. Successful field expeditions result in a wealth of material brought back to a museum or repository – but the time required to prepare, study and publish on fossils means these institutions typically <a href="https://theconversation.com/digitizing-the-vast-dark-data-in-museum-fossil-collections-102833">hold many more specimens than they can display</a>. Important discoveries can be made by collecting specimens on expeditions in remote locations, no doubt. But equally important discoveries can be made by simply processing the backlog of specimens already on hand.</p><img src="https://counter.theconversation.com/content/148772/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter A. Kloess 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>Paleontologists have discovered fossil remains belonging to an enormous ‘toothed’ bird that lived for a period of about 60 million years after dinosaurs.Peter A. Kloess, Doctoral Candidate, Integrative Biology, University of California, BerkeleyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1398802020-06-14T08:13:41Z2020-06-14T08:13:41ZWhat’s behind hundreds of vulture deaths in Guinea-Bissau. And what can be done<figure><img src="https://images.theconversation.com/files/339715/original/file-20200604-67393-cz30d5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A Hooded Vulture </span> <span class="attribution"><span class="source">JOHN THYS/AFP via Getty Images</span></span></figcaption></figure><p><em>More than <a href="https://africageographic.com/stories/648-vultures-dead-in-guinea-bissau/">2,000</a> critically endangered Hooded Vultures are reported to have died in Guinea-Bissau since 2019. They were deliberately poisoned with an agricultural pesticide. These killings are the largest incident of mass vulture deaths in the world. Dr Beckie Garbett explains why people are targeting the vultures and what must be done to stop it.</em></p>
<p><strong>How big is the vulture population in the region?</strong></p>
<p>There are six resident vulture species in West Africa: the Palm-nut Vulture, White-backed Vulture, Ruppell’s Vulture, Hooded Vulture, White-headed Vulture and Lappet-faced Vulture. All but the Palm-nut Vulture are either endangered or critically endangered due to populations being decimated by human activities, mainly poisoning. Some species have declined by <a href="https://conbio.onlinelibrary.wiley.com/doi/full/10.1111/conl.12182">as much as 97%</a> in recent years. Some of the largest declines have occurred even within protected areas. </p>
<p>It’s not known exactly how many vultures there are in West Africa, but some countries are certainly regional strongholds, meaning that they hold a significant proportion of the entire species’ population. For example, Guinea-Bissau <a href="https://www.researchgate.net/figure/Hooded-Vulture-range-population-trends-and-value-of-information-from-range-countries_fig1_233170924">holds important</a> global populations of Hooded and White-backed Vultures. Both are critically endangered species.</p>
<p><strong>Why are vultures being poisoned in Guinea-Bissau and does it happen often?</strong></p>
<p>The information we have has come from field teams, <a href="https://www.von.gov.ng/conservation-organisations-launch-online-petition-against-vulture-killings/">led by</a> a national NGO – the Organisation for the Defence and Development of Wetlands in Guinea-Bissau. They report that over 2,000 vultures have died in the various incidents across Guinea-Bissau since 2019. Many of the dead vultures were beheaded, which suggests that the body parts were harvested for ‘medicinal’ or belief-based purposes. </p>
<p>Belief-based use is <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0190594">essentially</a> traditional or superstitious use of wildlife products, in this case vulture body parts. These beliefs about medicinal or magical qualities are not founded on evidence. Belief-based use of wildlife is a practice that is <a href="https://www.researchgate.net/publication/229392791_Major_declines_in_the_abundance_of_vultures_and_other_scavenging_raptors_in_and_around_the_Masai_Mara_ecosystem_Kenya">prevalent</a> in West Africa. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/339215/original/file-20200602-133851-uas8t9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/339215/original/file-20200602-133851-uas8t9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/339215/original/file-20200602-133851-uas8t9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/339215/original/file-20200602-133851-uas8t9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/339215/original/file-20200602-133851-uas8t9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/339215/original/file-20200602-133851-uas8t9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/339215/original/file-20200602-133851-uas8t9.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">Hooded Vultures wait for scraps of meat at Guinea-Bissau’s main slaughter house.</span>
<span class="attribution"><span class="source">Photo by JOHN WESSELS/AFP via Getty Images</span></span>
</figcaption>
</figure>
<p>In each case of poisoning, <a href="http://www.birdlifebotswana.org.bw/blb-statement-vulture-poisoning-incidents-motshereganyi-virat-kootsositse-director-%E2%80%93-birdlife">hundreds</a> or <a href="https://www.4vultures.org/biggest-ever-vulture-mortality-event-in-the-world-unfolds-in-guinea-bissau-estimates-of-over-2000-hooded-vultures-poisoned-to-death-due-to-belief-based-use/">thousands</a> of vultures can be wiped out in one go. These recent incidents however are some of the worst I’ve seen.</p>
<p><strong>What does it mean for the species as a whole in the region?</strong></p>
<p>The poisoning incident in Guinea-Bissau represents a loss of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5791984/">around 5%</a> of the estimated national population of Hooded Vultures, which represents <a href="https://www.iucnredlist.org/species/22695185/118599398">22%</a> of the entire global population. Losses of this magnitude of a species already on the brink of extinction are unfathomable. It’s a huge setback for conservation efforts across Africa, and severely threatens the persistence of regional populations of this species. </p>
<p>Hooded Vultures aren’t the only species at risk in West Africa. Other endangered and critically endangered species such as Lappet-faced Vultures and White-backed Vultures are also regularly found <a href="https://www.cambridge.org/core/services/aop-cambridge-core/content/view/C3FEA745D94B56C84E7B4BB46E3A4A1D/S0030605315000514a.pdf/div-class-title-trade-of-threatened-vultures-and-other-raptors-for-fetish-and-bushmeat-in-west-and-central-africa-div.pdf">in trade markets</a> across the region. </p>
<p>Almost all African vulture species are in steep decline. To save them, poisoning for any purpose has to stop.</p>
<p><strong>What can be done to put a stop to it?</strong></p>
<p>There are a few steps that must be taken: raise awareness, involve the community and deal with the method of poisoning.</p>
<p>In Guinea-Bissau, BirdLife – a global partnership dedicated to the conservation of birds – is supporting the roll-out of an <a href="http://www.birdlife.org/worldwide/news/investigating-mystery-behind-guinea-bissaus-mass-vulture-deaths">Emergency Action Plan</a> in response to the recent poisoning incidents through a national partner organisation. This aims to gather circumstantial information and mortality data through social surveys. It will also raise awareness of the vulture killings and impacts of wildlife poisoning. </p>
<p>But there are only limited resources and Guinea-Bissau is politically unstable. This means that responsive actions are limited, but hopefully can be developed with additional support from NGOs such as BirdLife and other International Agencies. </p>
<p>For instance, in Nigeria, BirdLife is <a href="https://www.ncfnigeria.org/component/k2/item/342-ncf-launch-a-2-year-vulture-conservation-project">working with</a> its national partner, the Nigerian Conservation Foundation, to address the same threat: belief-based use and illegal trade of vultures. They work with traditional healers’ associations, hunters and traders of wildlife products to advocate for the use of plant-based alternatives to vultures. They also support law enforcement agencies in dealing with illegal trade. This has proven to be a <a href="https://allafrica.com/stories/202002120620.html">very successful</a> approach. Getting buy-in from key people involved in the sourcing, sales and use of vultures and wildlife products in general is essential for making a meaningful and sustainable impact.</p>
<p>With regard to tackling the method of killing – poisoning – ongoing work by conservation NGOs, such as Nature Kenya (BirdLife Partner in Kenya), has established <a href="https://www.birdlife.org/worldwide/news/saving-sentinels-skies-kenyas-rapid-response-vulture-unit">a model</a> that can be rolled out into other areas. This involves creating anti-poisoning networks within local communities to rapidly detect and respond to poisoning incidents in poison hotspot areas. The response protocol streamlines responses from multiple stakeholders, as well as providing guidelines for preservation and collection of forensic evidence in order to facilitate identification of substances used in poisonings and aid apprehension and prosecution of offenders of wildlife crimes. </p>
<p>In addition to the protocol, in January 2019, the Kenyan government <a href="https://www.nationalgeographic.com/animals/2019/11/vultures-saved-poisoning-kenya/">amended</a> the 2013 Kenyan Wildlife Act to make wildlife poisoning a standalone crime punishable with a fine of about $50,000 or five years in prison.</p>
<p>In Kenya, vulture poisoning is being increasingly detected and mitigated because of this model. The Kenya Wildlife Service has officially mainstreamed the wildlife poisoning response protocol into its operations policy. </p>
<p>Addressing the complex threats to African vultures requires a multi-pronged approach that has integrated local-level actions at its core.</p><img src="https://counter.theconversation.com/content/139880/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Beckie Garbett does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The poisoning incident in Guinea-Bissau represents a loss of around 5% of the estimated national population of Hooded Vultures, which makes up 22% of the entire global population.Beckie Garbett, Doctoral student at the Percy Fitzpatrick Institute, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1068702018-11-16T13:45:28Z2018-11-16T13:45:28ZHow vultures use each other as guides through the turbulent skies<figure><img src="https://images.theconversation.com/files/245932/original/file-20181116-194488-1bqizua.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Gyps fulvus gliding out from les Rocher des Aigles ornithological centre, France, carrying bio-logging tag</span> <span class="attribution"><span class="source">Hannah Williams</span></span></figcaption></figure><p>How would you move through a space when you can’t see the obstacles ahead? For example, how would you find your way out of a maze if you were blindfolded? You could either use your other senses, such as touch, to find your way out – or better yet, you could get someone who can see the way out to direct you. But either way you need information.</p>
<p>For birds, non-visual information can provide the same helping hand while flying. Even though they can see the world around them, the air is a dynamic, invisible environment – and airflow is much more complex environment to move through than the ground with its static obstacles.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/245823/original/file-20181115-194500-1ihuqfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/245823/original/file-20181115-194500-1ihuqfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/245823/original/file-20181115-194500-1ihuqfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/245823/original/file-20181115-194500-1ihuqfx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/245823/original/file-20181115-194500-1ihuqfx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/245823/original/file-20181115-194500-1ihuqfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/245823/original/file-20181115-194500-1ihuqfx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/245823/original/file-20181115-194500-1ihuqfx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Gyps vultures taking off for group flight.</span>
<span class="attribution"><span class="source">Hannah Williams</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Imagine you are hanging from a glider and racing to a finish line. You can see two other paragliders ahead of you, one looks like they are having a smooth ride and moving quickly, the other looks like they are in trouble and finding it difficult to control their glider. You would choose to follow the first one, right? By observing the other pilots around you and responding in accordance to what happens to them, you tap into information that helps you make a good decision and keep up with the race. Similarly, it makes sense that an animal may do the same to move through their environment – observing those around them that have the same objective.</p>
<p>Soaring birds not only move through the air, they rely on updrafts, such as thermals (a column of warm rising air), to gain lift rather than flapping their wings. It’s a bit like a big game of invisible snakes and ladders – but the costs of sliding all the way down without finding the next ladder are high. They must reach that next ladder before they hit the ground. Like the gliders, birds that rely on soaring – including vultures – often share the air with other birds. But until now we didn’t know if soaring birds do indeed observe each other to “see” these invisible thermal ladders.</p>
<h2>Invisible ladders</h2>
<p>For our <a href="http://rsif.royalsocietypublishing.org/content/15/148/20180578">recently published study</a>, we designed an experiment that would test this idea. We tracked the movements of each bird in a small group of vultures at a <a href="http://www.rocherdesaigles.com/ornithological-park-france-rocamadour.html">bird of prey centre</a> in the mountains of France, and recorded their behaviour. Only by using the latest tagging technology could we investigate this concept. Each bird had a backpack with a GPS logger, a movement logger and <a href="https://youtu.be/mSG-nqTbMR0">camera</a> recording all aspects of their movement. In the movement logger was a range of sensors, sensitive to different movement types – an accelerometer to pick up wing beats, a magnetometer for directional changes, and an airspeed sensor. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/245940/original/file-20181116-194497-x8oaw1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/245940/original/file-20181116-194497-x8oaw1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/245940/original/file-20181116-194497-x8oaw1.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/245940/original/file-20181116-194497-x8oaw1.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/245940/original/file-20181116-194497-x8oaw1.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/245940/original/file-20181116-194497-x8oaw1.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/245940/original/file-20181116-194497-x8oaw1.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">An onboard camera shows two Gyps vultures soaring in the same thermal.</span>
<span class="attribution"><span class="source">Hannah Williams</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>There is <a href="https://flybubble.com/blog/speed-to-fly-basics">a well known theory</a>, by aeronautical engineer Paul MacCready, which states that birds and gliders should glide at high airspeed when they have just left a strong thermal and expect to be approaching another strong thermal. But gliding quickly is risky, as the flyer is more likely to hit the ground before reaching the next thermal. So our hypothesis was that these vultures, and other soaring birds, are able to take this risk and glide quickly when they have clues provided by the soaring of others, on the whereabouts of the next thermal. </p>
<p>When we mapped the movements of all the vultures and analysed their gliding airspeeds, we found that – on making a decision to leave one thermal and glide to the next – vultures which had tapped into this extra information by “eavesdropping” on the movements of others (they weren’t flocked together but were watching how the other vultures were acting) chose to take the risk and adopt significantly higher airspeeds than those going it alone. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/245937/original/file-20181116-194506-1o65ulb.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/245937/original/file-20181116-194506-1o65ulb.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/245937/original/file-20181116-194506-1o65ulb.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=457&fit=crop&dpr=1 600w, https://images.theconversation.com/files/245937/original/file-20181116-194506-1o65ulb.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=457&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/245937/original/file-20181116-194506-1o65ulb.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=457&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/245937/original/file-20181116-194506-1o65ulb.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=574&fit=crop&dpr=1 754w, https://images.theconversation.com/files/245937/original/file-20181116-194506-1o65ulb.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=574&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/245937/original/file-20181116-194506-1o65ulb.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=574&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">GPS tracks of two Gyps vultures flying above Rocamadour, France.</span>
<span class="attribution"><span class="source">Hannah Williams</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>This finding helps us to understand what is going on in the invisible world above us and just how these birds make decisions to navigate this challenging environment. We are all quite used to seeing birds such as pigeons or starlings flying in flocks, and it may be quite reasonable to assume that by flying together these birds are interacting with each other. But our work reveals for the first time that even when birds are not flying together in a flock, they may observe others to sense the world around them. This suggests, for vultures at least, that it is important that there are other birds in the sky with them, as numbers may be needed to maintain a healthy network of information.</p><img src="https://counter.theconversation.com/content/106870/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Hannah Williams 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>Even when birds are not flying in a flock, they may observe each other to sense the world around them.Hannah Williams, Postdoctoral research associate, Swansea UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/494552015-10-20T23:27:16Z2015-10-20T23:27:16ZVultures in crisis: poachers and poison threaten nature’s garbage disposers<figure><img src="https://images.theconversation.com/files/99030/original/image-20151020-32225-1ut6nfg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Just doing their bit for the ecosystem.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/jjmusgrove/11971018196/">jjmusgrove</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Vultures are nature’s garbage disposers. They’re perfectly adapted to keep the environment clean and healthy by efficiently locating and consuming carcasses, recycling energy through the food web and preventing the spread of diseases. It’s an unpaid role. However it’s about time we did start repaying vultures for their services, by giving them the protection they deserve.</p>
<p>A new study published in the journal <a href="http://dx.doi.org/10.1186/s13059-015-0780-4">Genome Biology</a> illustrates just how finely-tuned these birds are. The researchers perform a whole genome analysis of the Eurasian cinereous vulture (<em>Aegypius monachus</em>) and reveal a unique genetic make-up that explains vultures’ strongly acidic digestive system and their ability to resist infection from pathogens present in the rotting carcasses on which they feed.</p>
<p>It’s even possible vultures are able to <a href="http://www.nature.com/news/microbes-help-vultures-eat-rotting-meat-1.16345">exploit the flesh-eating properties of some bacteria</a> to aid with the digestion of soft tissues and <a href="http://sora.unm.edu/sites/default/files/journals/jrr/v028n02/p00073-p00078.pdf">bones</a>, while the secretion of <a href="http://www.ncbi.nlm.nih.gov/pubmed/239254">corrosive gastric acids</a> and specialised immune responses allow them to resist infection from, and potentially even destroy, highly infective pathogens such as <a href="http://www.ncbi.nlm.nih.gov/pubmed/18788202">anthrax</a> and brucellosis.</p>
<p>This unusual tolerance of natural toxins doesn’t protect vultures from man-made contaminants however, which explains why <a href="http://onlinelibrary.wiley.com/doi/10.1111/conl.12182/pdf">69% of vulture and condor species are listed as threatened or near-threatened</a>, most of which are classed as “endangered” or “critically endangered”. The California condor (<em>Gymnogyps californianus</em>), for instance, was <a href="http://www.iucnredlist.org/details/22697636/0">declared extinct in the wild</a> in 1987 when the last remaining individuals were removed and placed in captivity to protect them from lead poisoning from ingesting shot and bullet fragments from hunted carcasses. Although captive-breeding and release programs have allowed the wild population to increase to more than 200 individuals, <a href="http://onlinelibrary.wiley.com/doi/10.1111/cobi.12342/abstract">lead poisoning continues to cause fatalities</a>.</p>
<p>Across Asia the big problem is accidental poisoning by diclofenac, an anti-inflammatory used to treat cattle. In vultures and some eagle species, tiny traces of the drug can lead to fatal kidney failure within 48 hours. In just 15 years, cow carcasses contaminated with diclofenac <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1749-6632.2011.06293.x/abstract?userIsAuthenticated=false&deniedAccessCustomisedMessage=">nearly wiped out</a> three of Asia’s vulture species.</p>
<p>This had a big knock-on effect. With less competition at carcass disposal dumps, where people once let vultures pick dead animals clean, India’s feral dog population exploded. This caused higher rates of rabies transmission at an estimated <a href="http://www.sciencedirect.com/science/article/pii/S092180090800178X">additional cost of US$34 billion</a> to the country’s healthcare between 1993 and 2006.</p>
<p>Although some <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0049118">populations have started to recover</a> following the ban of diclofenac in India in 2006, a logic-defying 2013 approval to licence the drug for use in Europe <a href="http://onlinelibrary.wiley.com/doi/10.1111/cobi.12271/abstract">now threatens vultures there</a> too, particularly in <a href="http://www.birdlife.org/europe-and-central-asia/project/ban-veterinary-diclofenac">Spain and Italy</a>. In Spain, replacing the natural carcass disposal service provided by vultures with vehicle transport to processing plants would result in the equivalent of an additional 77,344 metric tons of CO<sub>2</sub> being emitted to the atmosphere and US$50m of additional payments to insurance companies each year, according to a <a href="http://www.nature.com/articles/srep07811">2014 study in Nature</a>.</p>
<h2>Global decline</h2>
<p>The situation in Africa is just as grim – “<a href="http://onlinelibrary.wiley.com/doi/10.1111/conl.12182/full">another continental vulture crisis</a>”, as one group of researchers described it earlier this year. Populations of seven species have declined by more than 80% in three generations, giving rise to calls for <a href="http://www.birdlife.org/globally-threatened-bird-forums/2015/07/proposed-status-changes-for-six-species-of-african-vulture/">six of those</a> to be listed as “critically endangered”. </p>
<p>Once again man-made toxins and illegal activities are to blame. Poisoning accounts for 61% of vulture deaths, 29% are attributed to the <a href="http://www.sciencedirect.com/science/article/pii/S000632071530063X">trade in vulture heads and brains</a> for <a href="http://www.telegraph.co.uk/news/worldnews/africaandindianocean/southafrica/6895577/South-Africans-smoke-vulture-brains-to-bring-lottery-luck.html">local cultural beliefs</a># and 9% of fatalities are caused by electrocution or collision with <a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8382151">power lines</a>.</p>
<p>Widespread poisoning is certainly the <a href="http://cmsdata.iucn.org/downloads/poison_position_statement__final_sep2014.pdf">most immediate threat</a>. Usually this happens after farmers target lions, leopards or hyenas that have been attacking their livestock. Vultures consume the poisoned predators or the baited carcass itself and subsequently become secondary, inadvertent victims.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/HVD-ua1AYQY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">One poisoned elephant carcass could infect many vultures.</span></figcaption>
</figure>
<p>However the booming illegal trade in ivory and rhino horn is also bad news for them, as poachers don’t want hundreds of circling vultures pointing authorities towards recently-killed elephants or rhinos. Poachers are therefore deliberately targeting the birds by lacing carcasses with poisons – even after they’ve left with the tusks or horns. More than <a href="http://www.namibian.com.na/index.php?id=112821&page=archive-read">500 vultures were poisoned</a> at a single poached elephant carcass in Namibia in July 2013, and the recent discovery of at least <a href="http://www.theguardian.com/world/2015/oct/14/bodies-of-dozens-of-elephants-found-poisoned-in-zimbabwe">26 elephants poisoned at cyanide-laced water holes</a> in Zimbabwe will also likely result in many vulture deaths.</p>
<h2>Vultures need better PR</h2>
<p>Why isn’t this a bigger scandal? After all, as many, if not more vultures are being killed in southern Africa each year as <a href="https://www.savetherhino.org/rhino_info/poaching_statistics">rhinos</a> or elephants. Perhaps these big, bald, flesh-eating birds are perceived as sinister and lacking enough “cute factor”.</p>
<p>But while vultures don’t share the good looks of penguins or puffins, the ecosystem services they provide are irreplaceable. They compete with – and control – populations of blowfly larvae, rats, feral dogs and other scavengers, many of which are disease vectors. They ultimately make the world cleaner and healthier.</p>
<p>In fact, the ecological niche occupied by today’s vulture species is so specialised that two unrelated groups evolved on opposite sides of the world to become the primary scavengers in their ecosystems. “Old World” vultures from Eurasia and Africa and “New World” vultures and condors from the Americas might look and act the same but as the <a href="http://dx.doi.org/10.1186/s13059-015-0780-4">latest study highlights</a> they don’t share a recent common ancestor, having diverged in evolutionary terms more than 60m years ago. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/99080/original/image-20151020-32269-142ukzn.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/99080/original/image-20151020-32269-142ukzn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/99080/original/image-20151020-32269-142ukzn.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=371&fit=crop&dpr=1 600w, https://images.theconversation.com/files/99080/original/image-20151020-32269-142ukzn.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=371&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/99080/original/image-20151020-32269-142ukzn.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=371&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/99080/original/image-20151020-32269-142ukzn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=467&fit=crop&dpr=1 754w, https://images.theconversation.com/files/99080/original/image-20151020-32269-142ukzn.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=467&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/99080/original/image-20151020-32269-142ukzn.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=467&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Lappet-faced (left, Old World) and turkey vultures evolved on different continents.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/lipkee/2853902720/;%20https://www.flickr.com/photos/livenature/11617745643/">Lip Kee Yap; Franco Folini</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>This is a classic example of “convergent evolution” – while Old World vultures share a common ancestry with eagles and New World species are more closely related to storks, they independently evolved similar specialisations to fulfil the important role of recycling carrion.</p>
<p>It’s time for us to appreciate these unique and highly-specialised birds. We must restrict harmful veterinary drugs, control illegal poisoning, provide uncontaminated sources of food and reduce the impact of power lines and wind farms. This must happen immediately to avoid a worldwide vulture crisis – and all of the negative implications for our own health and well-being.</p><img src="https://counter.theconversation.com/content/49455/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Louis Phipps 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>They might keep the environment clean and healthy but most species are in steep decline.Louis Phipps, Conservation Biologist, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/436772015-06-29T04:20:49Z2015-06-29T04:20:49ZWhat can be done to make sure that wind energy and Africa’s vultures co-exist<figure><img src="https://images.theconversation.com/files/86546/original/image-20150626-1398-6d5h2o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Badly sited wind farms may pose a threat to Bearded Vultures in southern Africa</span> <span class="attribution"><span class="source">Shane Elliott</span></span></figcaption></figure><p>Many people see wind energy as one of the key solutions to meeting Africa’s growing energy demand and mitigating climate change. As a result, wind farms are already under <a href="http://www.afdb.org/fileadmin/uploads/afdb/Documents/Publications/Working%20Paper%20170%20-%20Development%20of%20Wind%20Energy%20in%20Africa.pdf">construction</a> or are being planned in many countries across sub-Saharan Africa. But wind farms can pose real threats to bird species, and they have the <a href="http://www.livescience.com/31995-how-do-wind-turbines-kill-birds.html">potential</a> to jeopardise threatened bird populations.</p>
<p>So far, the biggest impact of inappropriately sited wind turbines has been on populations of large <a href="http://science.howstuffworks.com/environmental/green-science/wind-turbine-kill-birds.htm">birds of prey</a>, in particular eagles and vultures. In some extreme cases turbines have led to the death of <a href="http://www.carbonbrief.org/blog/2013/04/wind-farms-and-birds/">hundreds</a> of the birds as they collide with the turning blades.</p>
<h2>Europe and America provide useful lessons</h2>
<p>Wind energy has the advantage of being an established energy source. But we also know from experiences in Europe and the US that inappropriately sited wind farms can have a devastating <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1474-919X.2006.00516.x/full">impact</a> on the environment.</p>
<p>For example, hundreds of raptors are killed <a href="http://news.nationalgeographic.com/news/energy/2014/04/140427-altamont-pass-will-newer-wind-turbines-mean-fewer-bird-deaths/">each year</a>, including relatively large numbers of <a href="http://onlinelibrary.wiley.com/doi/10.2193/2007-032/abstract">Golden Eagles</a> at the wind farm at Altamont Pass, California. Turbines at the Smøla Island wind farm in Norway have also had a terrible effect on <a href="http://onlinelibrary.wiley.com/doi/10.1002/wsb.258/abstract">White-tailed Eagles</a>.</p>
<p>Africa has the opportunity to benefit from lessons learned in Europe and North America. Experiences there can help ensure that wind farms are not placed in areas likely to conflict with vulnerable bird populations. They can also advance our knowledge on how wind farms can be constructed in a sustainable way without destroying the very species they hope to ultimately protect from the negative impacts of climate change.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/86548/original/image-20150626-1405-u97zhh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/86548/original/image-20150626-1405-u97zhh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/86548/original/image-20150626-1405-u97zhh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/86548/original/image-20150626-1405-u97zhh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/86548/original/image-20150626-1405-u97zhh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/86548/original/image-20150626-1405-u97zhh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=533&fit=crop&dpr=1 754w, https://images.theconversation.com/files/86548/original/image-20150626-1405-u97zhh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=533&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/86548/original/image-20150626-1405-u97zhh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=533&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Wind farms such as these place birds at risk of death.</span>
<span class="attribution"><span class="source">Stefan Wermuth/Reuters</span></span>
</figcaption>
</figure>
<h2>Lesotho is a prime site</h2>
<p><a href="http://www.nationsonline.org/oneworld/lesotho.htm">Lesotho</a> is the only independent state to lie entirely above 1000m elevation and is one of the <a href="https://www.gfmag.com/global-data/economic-data/the-poorest-countries-in-the-world">poorest countries</a> on the planet. It is a prime location for wind energy production which has the added advantage of bringing in much needed <a href="http://china.aiddata.org/projects/1407">revenue</a> and creating jobs.</p>
<p>But the Lesotho mountains also lie at the centre of the <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0114920">Bearded Vulture</a> population in southern Africa, a species particularly <a href="http://www.birdlife.org/datazone/sowb/casestudy/567">vulnerable</a> to the impact of wind farms. </p>
<p>Bearded vultures are classified within this region as critically endangered. They have declined by at least 30% over the last few decades. Only around 100 pairs <a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9269641&fileId=S0959270913000440">remain</a>. The main causes of the decline are linked to <a href="http://www.aoucospubs.org/doi/full/10.1650/CONDOR-14-121.1">poisoning and collisions</a> with power lines.</p>
<p>Lesotho currently has no wind farms but large scale developments are being <a href="http://china.aiddata.org/projects/1407">planned</a> in the <a href="http://www.windpowerintelligence.com/article/aziImxOkBhI/2014/02/05/lesotho_42-turbine_letseng_wind_farm_receives_approval/">Letseng</a> and Oxbow areas. The Letseng project, consisting of 42 turbines, has already been <a href="http://www.birdlife.org/africa/news/controversial-wind-farm-lesotho-gets-go-ahead">approved</a>. There are also longer-term plans for multiple wind farms made up of 4000 turbines generating around <a href="http://china.aiddata.org/projects/1407">6000 megawatts</a> throughout the Lesotho highlands.</p>
<h2>Minimising the impact</h2>
<p>This can be achieved in two ways. </p>
<p>The first is <a href="http://grist.org/climate-energy/for-the-birds-and-the-bats-8-ways-wind-power-companies-are-trying-to-prevent-deadly-collisions/">ensuring</a> that wind farms are not developed in areas where vulnerable species occur. This can be done by building sensitivity maps that highlight the best and worst locations at a very broad scale of where to place wind farms within a country. A <a href="http://www.birdlife.org.za/conservation/terrestrial-bird-conservation/birds-and-renewable-energy/wind-farm-map">map</a> like this has been successfully completed for South Africa by <a href="http://www.birdlife.org.za/">BirdLife South Africa</a> and the <a href="https://www.ewt.org.za/">Endangered Wildlife Trust</a>.</p>
<p>The second approach aims to ensure that, where wind farms and vulnerable species do overlap, turbines are sited in the most appropriate locations to decrease the <a href="http://www.abcbirds.org/abcprograms/policy/collisions/wind_faq.html">risk</a> of collision. This approach is difficult because it requires detailed information on the habitat use of species which is only rarely available. </p>
<p>But this kind of data would make it possible to build predictive models which could be applied across a species’ range to identify inappropriate locations for turbines.</p>
<h2>31 bird-years of vulture data</h2>
<p>In our new <a href="http://onlinelibrary.wiley.com/doi/10.1111/1365-2664.12468/abstract">study</a>, we applied this second approach to identify high use areas for the Bearded Vulture in Lesotho and neighbouring provinces in South Africa. Our aim was to provide a tool that would allow developers to site wind farms in locations least damaging to Bearded Vultures.</p>
<p>We took advantage of tracking <a href="http://www.fitzpatrick.uct.ac.za/docs/sonja.html">data</a> collected from 21 Bearded Vultures fitted with solar-powered GPS satellite tags. Between 2007 and 2012 these tags generated the equivalent of 31 bird-years of data logging the vultures’ location, altitude and speed every hour during daylight.</p>
<p>Working with a spatial <a href="http://www.fitzpatrick.uct.ac.za/docs/tim_reid.html">ecologist</a>, we used the data to construct models that predicted which areas would be most intensively used by Bearded Vulture. Separate models were built for territorial adults and sub-adults because they behave <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0114920">differently</a>. </p>
<p>Next we refined these models incorporating the probability of flying at heights that place the birds at risk of collision. This is less than 200m. Our final model combined probability of being at risk height and allowed the generation of a risk map covering the entire southern Africa range of the species.</p>
<p>We tested the use of the map with the two proposed wind farms and explored their levels of risk relative to other sites within the species range. We found that the two proposed wind farms were very poorly sited, particularly the one at Letseng. This reinforced the findings of another <a href="http://www.tandfonline.com/doi/abs/10.2989/00306525.2014.913211">study</a> which suggested that fatalities from the wind farm could substantially increase the decline rate of this species. </p>
<p>The map is freely available to wind farm developers and can be used to guide future development. Based on the information it provides we hope wind farms will be sited away from high intensity areas used by Bearded Vultures. The map’s high resolution (90m x 90m) also means it can help guide the placement of individual turbines.</p>
<p>The model was built to test the feasibility of creating such a tool. We are now confident that this can be a useful approach to help other species threatened by wind farms.</p><img src="https://counter.theconversation.com/content/43677/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Arjun Amar received funding from DST-NRF Centre of Excellence at the Percy FitzPatrick Institute of African Ornithology, and from Natural Research Ltd, a Scottish based environmental charity.</span></em></p>Wind farms are responsible for a large number of bird deaths. Finding a way to ensure that they can co-exist is vital.Arjun Amar, Senior Lecturer, Percy FitzPatrick Institute of African Ornithology, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.