Like people, vultures get set in their ways and have fewer friends as they age

Older birds tend to have more selective friendships with stronger bonds and may know better where to find food

University of California - Los Angeles

Key takeaways

• Young griffon vultures move frequently between sleeping sites in different locations, interacting with many friends.
• They get set in their ways as they age and roost in the same spots with the same individuals; older vultures follow the same paths.
• Roosts act as information hubs; older vultures may have a more thorough knowledge of where to find food resources and less need to learn about them from other vultures.

If you’d rather be watching TV on your couch than dancing at the club, you might have something in common with aging griffon vultures. New research shows that young griffon vultures move frequently between sleeping sites in different locations and interact with many friends but get set in their ways as they age, roosting in the same spots with the same individuals. As moving between roosts becomes a grind, older vultures follow the same path, establishing movement routines, that are not seen in young vultures.

Younger vultures shy away from the most popular roosts, suggesting they might be intimidated by the older ones or that there’s a vulture equivalent of “Hey you kids, get off my lawn.”

The research, published in Proceedings of the National Academy of Sciences, shows that like many people, older vultures tend to have fewer, more selective friendships with stronger bonds. They may also have a more thorough knowledge of where to find food resources.

Eurasian griffon vultures, or Gyps fulvus, are large vultures that live in the Mediterranean, the Middle East and India. With wingspans up to 9 feet, they’re much larger than North American turkey vultures and bigger than bald eagles.

Finding food can be tricky for vultures because it depends on locating animal carcasses — an unpredictable and ephemeral source. When griffon vultures find a carcass, they tend to sleep or roost nearby and feed on it over a period of days. Roosting sites can thus be ‘information hubs,’ where vultures that recently fed signal to others about food sources; they then follow each other to carcasses and form friendships that help them stay in the loop about food.

The researchers wanted to know if an individual griffon vulture’s movement patterns and social behavior changed over the course of its life. They used GPS data from 142 individually tagged birds in Israel gathered over a period of 15 years to cross-reference the vultures’ ages with their movement and social interactions at roost sites.

“What we found was as they age, their loyalty to certain roost sites increases,” said co-author Noa Pinter-Wollman, a UCLA professor of ecology and evolutionary biology. “Young vultures check out many different roosts but in middle age, they start going repeatedly to the same places.”

The study showed young vultures sometimes returned to the same roost but usually chose different ones, rarely spending two nights in the same place. From young adulthood at around 5 years old through middle age, they spent about half their nights at the same “home” site and half elsewhere. In old age, they became true homebodies.

“When they are old, from the age of 10 onward, they no longer have the energy to be ‘out and about’ and return consistently to the same site,” said corresponding author Orr Spiegel of Tel Aviv University. “Those who were adventurous at the age of 5 became more sedentary by age 10.”

As the vultures grew older, the strength of their social bonds decreased as well for at least part of the year. The number of individuals they interacted with didn’t change with age — if they had five friends when young, they still had five when older. But the amount of time they spent with vultures outside of their close friend group plummeted. Older vultures spent most of their time with and roosted mostly with these close friends. Their movements also became more routine, eventually following a predictable pattern.

The study is unique because the researchers were able to track the movements and social behaviors of the same vultures for up to 12 nearly consecutive years over a 15-year period.

“We are able to show that the trends of individuals becoming more loyal to the same sites with age is not because the more exploratory individuals die earlier and live shorter lives, and the older, more sedentary individuals live longer lives,” said first author and Tel Aviv University postdoctoral fellow Marta Acácio. “Individuals actually change their behavior with age, and this has rarely been shown in nature for long-lived birds due to the difficulty of tracking individuals for such a long time.”

The research backs up findings from studies in other species that, with age, animals become more faithful to their known sites and routines — and potentially become more selective in their social relationships. These behaviors are commonly attributed to aging in humans and can help improve understanding of how animal populations move about in their environments and relate to other members of their species, as well as identify better ways to protect them from threats. For griffon vultures, this could mean better protection of important roosting sites and using knowledge about their social interactions to reduce the risk of poisoning.

“It looks like they just get set in their ways,” Pinter-Wollman said. “They’ve gathered information over the years, and they might as well use it. Carcasses are hard to come by and roosts are information hubs. Some roosts become popular for a reason; for example, they tend to be closer to reliable food sources and older vultures potentially monopolize these roosts.”

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Journal

Proceedings of the National Academy of Sciences

Latest trouble at the border: Vultures are defecating and urinating all over a CBP radio tower
The mess is coating the entire 320-foot tower in southern Texas that the agency needs to communicate. The birds are also vomiting onto buildings below the tower and dropping prey from hundreds of feet in the air, an agency spokesperson said.


 Hooded vultures wait for scraps of meat at Bissau's main slaughter house on November 26, 2019. - Tens of thousands of Hooded Vultures flock to the city of Bissau to in search of food left behind in heaps of garbage or around market areas. Photo by JOHN WESSELS / AFP

A radio tower for the US Customs and Border Protection near the US-Mexico border has been plagued by vultures that roost there and drop feces, vomit, and even prey on the buildings below.Around 300 vultures have taken over the tower in the past six years, Quartz reports, and have coated the structure with "droppings mixed with urine," as well as corrosive vomit that eats away at the metal.CBP spokesperson told Quartz that the birds create a "terrifying and dangerous" environment at the workplace, and said there are anecdotes of them dropping prey from as high as 300 feet in the air.The Migratory Bird Treaty Act prohibits killing the vultures, but CBP is planning to install a "viable netting deterrent" to stop the vultures from roosting in its radio towers.

For a radio tower and surrounding buildings operated by US Customs and Border Protection (CBP) near the Texas-Mexico border, vultures are no joke. Around 300 of the carnivorous birds have roosted in its radio tower, and are creating communications issues thanks to their corrosive vomit and feces.

Quartz reports that CBP filed a request for information that includes details about the problems the vultures have created at the radio tower, which is now entirely coated in "droppings mixed with urine" that have also fallen on the ground and surrounding buildings below, where people work and equipment is kept.

Furthermore, a CBP spokesperson told Quartz that workers have anecdotes of the vultures dropping prey from as high as 300 feet above, creating a "terrifying and dangerous" work environment for the past six years.
fernando sanchez/Shutterstock

Vultures regurgitate a corrosive vomit as a defense mechanism that can kill bacteria on their legs but also eat away at the metal radio tower, making it unsafe for maintenance workers to climb it and reducing the tower's lifespan.

Large groups of vultures also smell like corpses – the species is known, of course, for feeding on dead flesh, or carrion. Undigested bones and fur can be found at the base of where vultures roost.

But CBP can't kill the vultures, as the Migratory Bird Treaty Act made that illegal in 1918. Instead, the agency is searching for a "viable netting deterrent" to stop the vultures from roosting on the radio tower. CBP told Quartz that it's working with the Fish and Wildlife Agency, the USDA, environmental experts, and the Texas State Historical Preservation Officer to find a solution that doesn't harm any of the vultures.

The agency also says there are no nests or baby birds in the tower. There are plans to clean and repair the radio tower before installing nets by August, before the natural heavy roosting cycle begins in the fall. 

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Wing tags severely impair flight in African Cape Vultures

Study urges the use of leg bands for marking individuals instead of wing tags

MAX-PLANCK-GESELLSCHAFT

Research News

 

IMAGE: CAPE VULTURE WITH PATAGIAL (WING) TAG FITTED CORRECTLY TO THE PATAGIUM view more 

CREDIT: VULPRO

Conservationists who apply wing tags for identifying Cape Vultures--a species of African vulture that is vulnerable to extinction--are putting the birds' lives further at risk, a new movement ecology study has shown. Researchers from the Max Planck Institute of Animal Behavior in Germany and VulPro NPC in South Africa have demonstrated that Cape Vultures fitted with tags on their wings travelled shorter distances and flew slower than those fitted with bands around their legs. The research emphasises the importance of investigating the effects that tagging methods can have on the behaviour and conservation of species, prompting a shift towards the less invasive method of leg bands in the future study of Cape Vultures.

For over a decade, many conservationists and NGOs have been marking vultures by placing a tag on the wing area known as the patagium. Patagial tags have the advantage that they are large and conspicuous enough for individuals to be identified from far away. Leg bands are smaller in size, fitted around the tarsus of the vultures leg and thus, harder to notice and record the unique number.

"After receiving many grounded and injured vultures from incorrect placement of wing tags, we felt there was an immediate need to find out exactly what these tags were doing to the flight of birds and whether this technique was, in fact, hindering the species rather than protecting them," says senior author Kerri Wolter, CEO of VulPro NPC, a vulture conservation organisation in South Africa.

The study was motivated by recent VulPro NPC research, which highlighted how an incorrect patagial tag could cause injuries and result in the grounding of vultures. To find out how patagial tags affected the birds' flights, researchers from the Max Planck Institute used GPS devices to track 27 Cape Vultures (Gyps coprotheres) marked with either patagial tags or leg bands.

The GPS devices, which were mounted to the birds' backs, recorded the birds' positions as often as every minute for 24 hours a day. These recordings allowed researchers to investigate the birds' flight performance, including occurrence of flight, proportion of time spent flying in a day, daily distance travelled and ground speed.

Individuals equipped with patagial tags covered a much smaller area in comparison to the leg band group. They were less likely to take flight and, when doing so, flew at lower ground speed compared to individuals wearing leg bands.

"Although we did not measure the effects of patagial tags on body condition or survival, our results strongly suggest that patagial tags have severe adverse effects on vultures' flight performance," says first author Teja Curk, a PhD student at the Max Planck Institute of Animal Behavior.

Vultures are scavengers. By feeding on dead animals, they play an important role in the ecosystem due to the services they provide, such as preventing the spread of infectious diseases, recycling organic material into nutrients and stabilising food webs.

"Therefore, restricted flight potential and a reduction in the area covered by these birds, caused by improper tag attachment, can have far-reaching consequences at the ecosystem level," says co-author Kamran Safi, a group leader at the Max Planck Institute of Animal Behavior.

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Original publication Teja Curk, Martina Scacco, Kamran Safi, Martin Wikelski, Wolfgang Fiedler, Ryno Kemp and Kerri Wolter Wing tags severely impair movement in African Cape Vultures Animal Biotelemetry 9(11) 09 March 2021

CAPTION

Cape Vulture with a coloured leg band. By feeding on dead animals, vultures play an important role in the ecosystem due to the services they provide, such as preventing the spread of infectious diseases, recycling organic material into nutrients and stabilising food webs.

CREDIT

VulPro

 

Vultures and artificial intelligence(s) as death detectors: GAIA develops a high-tech approach for wildlife research and conservation

Leibniz Institute for Zoo and Wildlife Research (IZW)

 

image: 

AI data scientists and wildlife biologists analyse and interpret data from vulture tags and develop an Artificial Intelligence for behaviour recognition. The GAIA I³ Lab at the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) in Berlin brings together state of art expertise in Wildlife Biology and Artificial Intelligence development.

view more 

Credit: Photo by Jon A. Juarez

In order to use remote locations to record and assess the behaviour of wildlife and environmental conditions, the GAIA Initiative developed an artificial intelligence (AI) algorithm that reliably and automatically classifies behaviours of white-backed vultures using animal tag data. As scavengers, vultures always look for the next carcass. With the help of tagged animals and a second AI algorithm, the scientists can now automatically locate carcasses across vast landscapes. The algorithms described in a recently published article in the “Journal of Applied Ecology” are therefore key components of an early warning system that can be used to quickly and reliably recognise critical changes or incidents in the environment such as droughts, disease outbreaks or the illegal killing of wildlife.

The GAIA Initiative is an alliance of research institutes, conservation organisations and enterprises with the aim of creating a high-tech early warning system for environmental changes and critical ecological incidents. The new AI algorithms were developed by the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) in cooperation with the Fraunhofer Institute for Integrated Circuits IIS and the Tierpark Berlin.

The death of wildlife is an important process in ecosystems – regardless whether this is a regular case, such as the successful hunt of a predator, or an exceptional case caused by the outbreak of a wildlife disease, the contamination of the landscape with environmental toxins or illegal killing by people. For the investigation of mammalian species communities and ecosystems it is therefore important to systematically record and analyse these regular and exceptional cases of mortality. In order to achieve this, the GAIA Initiative makes use of the natural abilities of white-backed vultures (Gyps africanus) in combination with highly developed biologging technologies and artificial intelligence. “This combination of three forms of intelligence ­– animal, human and artificial – is the core of our new I³ approach with which we aim to make use of the impressive knowledge that wildlife has about ecosystems”, says Dr Jörg Melzheimer, GAIA project head and scientist at the Leibniz-IZW.

Vultures are perfectly adapted by millions of years of evolution to detect carcasses across vast landscapes quickly and reliably. They have outstanding eye-vision and sophisticated communication that allows them to monitor very large areas of land when many individuals work together. Vultures thus fulfil an important ecological role by cleaning landscapes of carrion and containing the spread of wildlife diseases. “For us as wildlife conservation scientists, the knowledge and skills of vultures as sentinels are very helpful to be able to quickly recognise problematic exceptional cases of mortality and initiate appropriate responses”, says Dr Ortwin Aschenborn, GAIA project head alongside Melzheimer at the Leibniz-IZW. “In order to use vulture knowledge, we need an interface – and at GAIA, this interface is created by combining animal tags with artificial intelligence.”

The animal tags with which GAIA equipped white-backed vultures in Namibia record two groups of data. The GPS sensor provides the exact location of the tagged individual at a specific point in time. The so-called ACC sensor (ACC is short for acceleration) stores detailed movement profiles of the tag – and thus of the animal – along the three spatial axes at the exact same time. Both groups of data are used by the artificial intelligence algorithms developed at the Leibniz-IZW. “Every behaviour is represented by specific acceleration patterns and thus creates specific signatures in the ACC data of the sensors”, explains wildlife biologist and AI specialist Wanja Rast from the Leibniz-IZW. “In order to recognise these signatures and reliably assign them to specific behaviours, we trained an AI using reference data. These reference data come from two white-backed vultures that we fitted with tags at Tierpark Berlin and from 27 wild vultures fitted with tags in Namibia.” In addition to the ACC data from the tags, the scientists recorded data on the behaviour of the animals – in the zoo through video recordings and in the field by observing the animals after they had been tagged. “In this way, we obtained around 15,000 data points of ACC signatures ascribed to a verified, specific vulture behaviour. These included active flight, gliding, lying, feeding and standing. This data set enabled us to train a so-called support vector machine, an AI algorithm that assigns ACC data to specific behaviours with a high degree of reliability”, explains Rast.

In a second step, the scientists combined the behaviour thus classified with the GPS data from the tags. Using algorithms for spatial clustering, they identified locations where certain behaviours occurred more frequently. In this way, they obtained spatially and temporally finely resolved locations where vultures fed. “The GAIA field scientists and their partners in the field were able to verify more than 500 of suspected carcass locations derived from the sensor data, as well as more than 1300 clusters of other non-carcass behaviours”, says Aschenborn. The field-verified carcass locations ultimately served to establish vulture feeding site signatures in the scientists’ final AI training dataset – this algorithm indicates with high precision locations where an animal has most likely died and a carcass is on the ground. “We could predict carcass locations with an impressive 92 percent probability and so demonstrated that a system which combines vulture behaviour, animal tags and AI is very useful for large-scale monitoring of animal mortality”, says Aschenborn.

This AI-based behaviour classification, carcass detection and carcass localisation are key components of the GAIA early warning system for critical changes or incidents in the environment. “Until now, this methodological step has been carried out in the GAIA I³ data lab at the Leibniz-IZW in Berlin”, says Melzheimer. “But with the new generation of animal tags developed by our consortium, AI analyses are implemented directly on the tag. This will provide reliable information on whether and where an animal carcass is located without prior data transfer in real time without any loss of time.” The transfer of all GPS and ACC raw data is no longer necessary, allowing data communication with a significantly lower bandwidth to transmit the relevant information. This makes it possible to use a satellite connection instead of terrestrial GSM networks, which guarantees coverage even in remote wilderness regions completely independent of local infrastructure. Even at the most remote locations, critical changes or incidents in the environment – such as disease outbreaks, droughts or illegal killing of wildlife – could then be recognised without delay.

In recent decades, the populations of many vulture species declined sharply and are now acutely threatened with extinction. The main causes are the loss of habitat and food in landscapes shaped by humans as well as a high number of direct or indirect incidences of poisoning. The population of the white-backed vulture, for example, declined by around 90 percent in just three generations – equivalent to an average decline of 4 percent per year. “Owing to their ecological importance and rapid decline, it is essential to significantly improve our knowledge and understanding of vultures in order to protect them”, says Aschenborn. “Our research using AI-based analysis methods will not only provide us with insights into ecosystems. It will also increase our knowledge of how vultures communicate, interact and cooperate, forage for food, breed, rear their young and pass on knowledge from one generation to the next.” GAIA has so far fitted more than 130 vultures in different parts of Africa with tags, most of them in Namibia. Until today, the scientists analysed more than 95 million GPS data points and 13 billion ACC records.

White-backed vultures and a jackal at a carcass 

Vultures are perfectly adapted by millions of years of evolution to detect carcasses across vast landscapes quickly and reliably. They have outstanding eye-vision and sophisticated communication that allows them to monitor very large areas of land when many individuals work together. Vultures thus fulfil an important ecological role by cleaning landscapes of carrion and containing the spread of wildlife diseases.

Credit

Photo by Jan Zwilling

The development of the AI algorithms require a distinct multi-step process that includes data acquisition in the wild and from vultures under human care, data annotation and AI training. The new AI algorithms were developed by the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) in cooperation with the Fraunhofer Institute for Integrated Circuits IIS and the Tierpark Berlin.

Credit

IIllustration by Clara C. Anders

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Journal

Journal of Applied Ecology

DOI

10.1111/1365-2664.14810 

Method of Research

Data/statistical analysis

Subject of Research

Animals

Article Title

Death detector: Using vultures as sentinels to detect carcasses by combining bio-logging and machine learning

Article Publication Date

18-Nov-2024

 

Turkey vultures fly faster to defy thin air

How large turkey vultures remain aloft in thin air

The Company of Biologists

Mountain hikes are invigorating. Crisp air and clear views can refresh the soul, but thin air presents an additional challenge for high-altitude birds. ‘All else being equal, bird wings produce less lift in low density air’, says Jonathan Rader from the University of North Carolina (UNC) at Chapel Hill, USA, making it more difficult to remain aloft. Yet this doesn’t seem to put them off. Bar-headed geese, cranes and bar-tailed godwits have recorded altitude records of 6000 m and more. So how do they manage to take to the air when thin air offers little lift? One possibility was that birds at high altitude simply fly faster, to compensate for the lower air density, but it wasn’t clear whether birds that naturally inhabit a wide range of altitudes, from sea level to the loftiest summits, might fine-tune their flight speed to compensate for thin air. ‘Turkey vultures are common through North America and inhabit an elevation range of more than 3000 m’, says Rader, so he and Ty Hedrick (UNC-Chapel Hill) decided to find out whether turkey vultures (Cathartes aura) residing at different elevations fly at different speeds depending on their altitude. They publish their discovery in Journal of Experimental Biology that turkey vultures fly faster at altitude to compensate for the lack of lift caused by flying in thin air.

First the duo needed to select locations over several thousand meters’ altitude, so they started filming the vultures flying at the local Orange County refuse site (80 m above sea level); ‘Vultures on a landfill… who would have guessed?’, chuckles Rader. Then they relocated to Rader’s home state of Wyoming, visiting Alcova (1600 m) before ending up at the University of Wyoming campus in Laramie (2200 m). At each location, the duo set up three synchronized cameras with a clear view to a tree that was home to a roosting colony of turkey vultures, ready to film the vultures’ flights in 3D as they flew home at the end of the day. ‘Wyoming is a famously windy place and prone to afternoon thunderstorms’, Rader explains, recalling being chased off the roof of the University of Wyoming Biological Sciences Building by storms and the wind blurring movies of the flying birds as it rattled the cameras.

Back in North Carolina, Rader reconstructed 2458 bird flights from the movies, calculating their flight speed before converting to airspeed, which ranged from 8.7 to 13.24m/s. He also calculated the air density at each location, based on local air pressure readings, recording a 27% change from 0.89kg/m3 at Laramie to 1.227 kg/m3 at Chapel Hill. After plotting the air densities at the time of flight against the birds’ airspeeds on a graph, Rader and Hedrick could see that the birds flying at 2200m in Laramie were generally flying ~1m/s faster than the birds in Chapel Hill. Turkey vultures fly faster at higher altitudes to remain aloft. But how do they achieve these higher airspeeds?

Rader returned to the flight movies, looking for the tell-tale up-and-down motion that would indicate when they were flapping. However, when he compared how much each bird was flapping with the different air densities, the high-altitude vultures were flapping no more than the birds nearer to sea level, so they weren’t changing their wingbeats to counteract the effects of low air density. Instead, it is likely that the 2200 m high birds were flying faster simply because there is less drag in thin air to slow them down, allowing the Laramie vultures to fly faster than the Chapel Hill birds to compensate for generating less lift in lower air density.

 

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REFERENCE: Rader, J. A. and Hedrick, T. L. (2024). Turkey vultures tune their airspeed to changing air density. J. Exp. Biol. 227, jeb246828. doi:10.1242/jeb.246828

DOI: 10.1242/jeb.246828

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Journal

Journal of Experimental Biology

DOI

10.1242/jeb.246828 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Turkey vultures tune their airspeed to changing air density

Article Publication Date

1-Aug-2024

 

Flamingos don’t preen more than other waterbirds

University of Exeter

 

image: 

Caribbean flamingo preening

view more 

Credit: Dr Paul Rose

Despite their famously fancy feathers, flamingos don’t spent more time preening than other waterbirds, new research shows.

Scientists watched five of the world’s six flamingo species to see how they spend their time.

While preening time varied, overall flamingos were roughly average compared to existing studies of other waterbirds.

The researchers also examined time spent standing on one leg – finding that captive flamingos most often do this indoors and in water.

The study was carried out by the University of Exeter and WWT Slimbridge Wetland Centre.

“It is widely believed – even among zookeepers – that flamingos spend more time than other birds preening their feathers,” said Dr Paul Rose, from Exeter’s Centre for Research in Animal Behaviour.

“But this hadn’t been tested until now – and we were surprised to find they are roughly ‘middle of the road’ among waterbirds.

“The waterbirds that spend the most time preening are actually Pelecaniformes such as pelicans, gannets and cormorants – which makes sense, as these birds spend the most time in water, and therefore need to maintain feathers for waterproofing.

“Even so, we expected flamingos to be top of the preening charts, as lush pink feathers are so important in their courtship displays.”

The study also found that captive waterbirds spend more time preening than wild birds.

Like many birds, flamingos stand on one leg to save energy and to allow half of their brain to sleep. By doing so in water, flamingos reduce heat loss (only one foot loses heat to the water, rather than two).

Rachael Kinnaird, who worked on the study as part of an MSc in Animal Behaviour at Exeter, said: “Our study shows the value of observing animals to understand their behaviour.

“In this case, a widely held belief about flamingos preening more than other waterbirds didn’t hold true.”

Commenting on the wider importance of the study, Dr Rose said: “By understanding why flamingos behave in certain ways, we can predict how climate and habitat change might affect them.

“At present, greater flamingos are seeing their range expand due to climate change. Meanwhile, mountain species such as Chilean and Andean flamingos are really suffering.

“Studying captive flamingos can help us understand what their wild counterparts need.

“We hold so many species in zoos around the world – so the opportunities to study them, to learn how and why they have evolved, are huge.”

The paper, published in the journal Applied Animal Behaviour Science, is entitled: “What influences feather care and unipedal resting in flamingos? Adding evidence to clarify behavioural anecdotes.”

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Chilean flamingo preening

hadean flamingo standing on one leg

Credit

Dr Paul Rose

Journal

Applied Animal Behaviour Science

DOI

10.1016/j.applanim.2024.106364 

Subject of Research

Animals

Article Title

What influences feather care and unipedal resting in flamingos? Adding evidence to clarify behavioural anecdotes

Article Publication Date

1-Aug-2024

It was long thought these fossils came from an eagle. Turns out they belong to the only known vulture species from Australia

The Conversation
July 21, 2022

The extinct species may have been a relative of the living Griffon Vulture (pictured). Shutterstock

In 1905, a fragment of a fossil wing bone discovered near the Kalamurina Homestead, South Australia, was described as an extinct eagle and named Taphaetus lacertosus, meaning “powerful grave eagle”.

Now research published by myself and mycolleagues can reveal this species was no eagle at all. It was an “Old World” vulture, which we have renamed Cryptogyps lacertosus, or “powerful hidden vulture”.

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 Cryptogyps likely died out with ancient Australia’s megafauna. There’s much about the species we’ve yet to find out.


Here’s me at the Flinders University palaeontology lab, holding the fossil vulture tarsus (left) and a tarsus of a living vulture species (right).
Author provided

A puzzling absence

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.

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.

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?

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.

The shape of a scavenger

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.

My colleagues and I wanted to find out if this really was the case, and so we began comparing the fossil bones of Cryptogyps to a wide range of living birds of prey, including vultures.


Being scavengers, vultures have a very different musculature and bone structure to eagles. This fact proved to be crucial in confirming Cryptogyps lacertosus was indeed a vulture.


A silhouette size comparison of a Wedge-tailed Eagle (left) and Cryptogyps lacertosus (right), and tarsi comparisons of both below.

Ellen Mather, Wedge-tailed Eagle silhouette derived from photo by Vicki Nunn.


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 Cryptogyps.

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.


To further test this, we placed the fossils in an evolutionary tree with other birds of prey. Our results confirmed what the comparison suggested: Cryptogyps was indeed a vulture, and potentially a close relative of the Griffon Vulture found across Europe and Asia.
The life and death of a species

Based on the leg bones, we can infer Cryptogyps didn’t actively hunt and grab prey with powerful talons. Rather, it would have scavenged dead animals as vultures do now.


At this point in time, we don’t have enough of the skeleton to know exactly what Cryptogyps lacertosus looked like, or what it ate.

It could have been a social species, gathering in large flocks around the corpses of megafauna such as Diprotodon or Protemnodon. 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.

Gaining this information will require more discoveries in the future. What isn’t in question, however, is that like all vultures today Cryptogyps lacertosus would have played an important role in ecosystem health.


Fossils of Cryptogyps 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.

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.

Other more generalist raptors such as Wedge-tailed Eagles and Black Kites subsequently filled the reduced scavenging niche.


The Wedge-tailed Eagle is the largest bird of prey in Australia today. Shutterstock

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.

And the consequences of this decline have been dire, including increased disease transmission in both animal and human populations, potential impacts on the nutrient cycle, and the restructuring of ecosystems.

Ellen K. Mather, Adjunct associate lecturer, Flinders University

This article is republished from The Conversation under a Creative Commons license. Read the original article.