Humans may face grave consequences if vultures disappear

When vulture populations in India suddenly started collapsing at the turn of the millennium, the consequences were far-reaching and unforeseen. 

Wild dogs took over the vultures’ job of eating carrion, their population exploded, and there was a significant increase in the number of people being bitten by dogs and contracting rabies. 

A group of researchers from the University of Bath in the UK and the Institute of Economic Growth in India concluded that the loss of vultures cost India over USD 30 billion, according to Norwegian newspaper Dagens Næringsliv (link in Norwegian. 

“Never before have humans had such a strong influence on the life on Earth as in our current era. We are in the middle of what many people are calling the sixth extinction,” Sara Asu Schroer explains. 

She is a postdoctoral research fellow at the University of Oslo and studies how the connection between humans and wild animals is shaped by human activities. 

Unlike the past five mass extinctions that spanned millions of years, the sixth, driven by human activity, is unfolding over just centuries.

“It's important to understand that when species, such as vultures, disappear from ecosystems, it can have vast and unforeseen consequences, also for us humans,” Schroer says.

Dramatic decline in animal populations

Schroer is head of the Living with Vultures in the Sixth Extinction research project. She explores the complex links between humans and vultures, and what is being done to preserve them in Europe.

The world’s animal populations have plummeted by 69 per cent since 1970, according to WWF’s 2022 Living Planet report.

Among those in peril are the world’s vulture populations, which have completely died out in several places.

The populations in Asia and Africa are the worst affected, while Europe is described as one of the last vulture strongholds – thanks in large part to various vulture conservation initiatives.

Vultures act as sentinel species

“Vultures are scavengers that live off the carcasses of wild and domestic animals. The fact that they live in such close proximity with humans and domestic animals makes them an interesting case for investigating how the relationship between humans and wild animals is affected by the fact that landscapes are increasingly being shaped by human activities,” Schroer says. 

Vultures also act as a sentinel species. This means that the health of vultures is an indicator of the health of the ecosystem as a whole.

In her research, Schroer wants to understand the ideas, values, and motivations of the people involved in vulture management and conservation measures.

“Since climate change and the environmental crises we are currently facing are anthropogenic, it's very important to include perspectives from the social sciences and the humanities in work to understand – and try to resolve – environmental problems,” she points out.

Successful reintroduction in the Alps

There are over 20 species of vultures in the world, including condors, which only live in North and South America. Europe is home to four native breeding vulture species – the Egyptian vulture, griffon vulture, cinereous vulture, and bearded vulture.

So far, Schroer’s research has primarily focused on the management of bearded vultures and griffon vultures.

Bearded vultures live in remote mountain areas such as the Alps and the Pyrenees, where they feed on carrion. Griffon vultures breed in large colonies, which can consist of up to hundreds of birds, and often range over open landscapes.

“Because griffon vultures occur in large groups and live near inhabited areas, they are far more visible than bearded vultures. Both have been hunted and have become endangered in most of their habitats in the past,” Schroer says. 

Since the late 1970s, there have been several breeding and reintroduction programmes in Europe aimed at bringing the birds back to places where they have died out.

“The rewilding of bearded vultures in the Alps is an iconic example of the successful reintroduction of a species into the wild by releasing birds bred in captivity. However, breeding vultures in captivity is no easy task," Schroer says.

She adds that the birds have a relatively long period of maturation, they may not want to mate with their allocated breeding partner, and they produce only one or two chicks a year. Breeding therefore takes a lot of patience and determination.

What is threatening vultures?

Historically, vultures have often been viewed as a threat by hunters and farmers, and have thus been hunted, both legally and illegally. 

In the 1970s, Europe started introducing more stringent environmental legislation, which has benefited vultures through a ban on hunting, among other things. More recently, however, new threats have started to emerge.

“A major problem in Europe is indirect poisoning through vultures feeding on poisoned carcasses that have been left out to kill predators such as wolves. Other common threats are veterinary drugs, toxins in the environment, and lead ammunition,” Schroer says. 

The vulture population in India suddenly collapsed because farmers started giving the anti-inflammatory drug diclofenac to livestock in the 1990s. The vultures died shortly after eating the carcasses because they could not tolerate the medicine. 

“Another big problem – and not just for vultures, but for birdlife in general – is the rapidly evolving renewable energy infrastructure, such as wind turbines and cables,” Schroer says.

Human and animal health are interconnected

Land-use change, resulting in habitat destruction, is the main driver of biodiversity loss today. One consequence of wild animals losing and being driven from their natural habitats is that they start living closer to humans.

“This means that the health of humans and domesticated animals, as well as the health of wild animals, are becoming more closely interlinked. A good example of this is the correlation between the outbreak of mad cow disease and the decline of the vulture populations in Europe,” Schroer says. 

Bovine spongiform encephalopathy (BSE), more commonly known as mad cow disease, was first detected in the UK in the mid-1980s. BSE developed as a result of the use of ground offal and bones of sheep and other domestic animals in cattle feed.

Following the BSE outbreak, a ban was introduced on farmers leaving animal carcasses out, as they might be a source of infection.

'Vulture restaurants' were established

No one thought about the consequences of this ban for vultures, and they began to starve. Some farmers even claimed that hungry vultures started attacking their livestock.

After pressure from conservation organisations, the legislation was amended, such that farmers could leave carcasses out in compliance with special rules. 

Additionally, feeding stations known as 'vulture restaurants' were also established.

“I think this example illustrates how we must learn to recognise that everything is connected to everything else in life. It is not possible to find sustainable ways of living if we think in isolated categories and address issues such as public health and environmental protection separately. Covid-19 is a good example of this. We humans are not outside the ecosystem, we are part of it,” Schroer says. 

Seabirds moving to the city

Schroer claims that studying the coexistence of vultures and humans in Europe up close provides useful knowledge about a number of general problems of our time.

“For example, in Norway we are seeing an alarming decline in seabird numbers,” she says. 

Lack of food, which in turn can be linked to climate change and overfishing, are believed to be the main cause. 

As a result, kittiwakes are moving into urban areas. They use rooftops like cliffs and make their nests there.

“This is leading to new conflicts and challenges in human-dominated environments,” she says. 

This content is paid for and presented by the University of Oslo

This content is created by the University of Oslo's communication staff, who use this platform to communicate science and share results from research with the public. The University of Oslo is one of more than 80 owners of ScienceNorway.no. Read more here.

More content from the University of Oslo:

• 

  Is TikTok ruining today's youth? Not at all, says media researcher

• 

  Humans have one characteristic that AI and robots are far from having

• 

  Call for action to tackle global antibiotic shortages

• 

  Researcher: There is an increased risk of nuclear weapons use

• 

  This newly developed robot can play the drums, listen, and learn

• 

  Genetically, this is a super fungus