This summer, as the snows finally melt across the Alps, a record 35 bearded vulture chicks are expected to leave their nests and take to the skies to patrol their mountain home, in one of the most successful wildlife comebacks of recent times.

“Bearded vultures were hunted to extinction in the Alps in the early 20th century. People referred to them as the devil bird believing that they would carry off small children and sheep,” said Théo Mazet, who works for Asters, a French wildlife organisation helping to bring the birds back to the Alps.

But attitudes have changed and the vultures have made a dramatic return, albeit with a helping hand.

“A captive breeding and reintroduction project began in the late 1980s and there are now a total of 250 birds, including 50 breeding pairs of bearded vultures in the Alps,” said Mazet.

Mazet works at a specialist captive breeding centre in a secluded forest high above the alpine town of Sallanches, one of five centres in the mountain range.

Bearded vultures were hunted to extinction in the Alps in the 20th century. Photograph: Hansruedi Weyrich

Here Mazet prepares food for the seven vultures housed in the centre’s massive aviary. He carefully weighs chunks of freshly butchered sheeps’ and goats’ legs for the birds – the only avian species to live on a diet of animal bones.

“Bearded vultures are scavengers and act as the rubbish collectors of the natural world which helps to eliminate potentially harmful bacteria and the spread of diseases, so keeping the mountain environment healthy,” he said.

Key to the project’s success has been the 100 captive vultures held in the breeding centres throughout Europe, which in turn are providing birds to be returned to the wild.

José Tavares, the director of the Vulture Conservation Foundation, which is spearheading the reintroduction of the bearded vulture across Europe, explains that they only use birds that have been bred in captivity rather than capturing and relocating birds from elsewhere.

The project has so far cost tens of millions of euros – so why spend so much money and effort on the reintroduction of one species?

“The bearded vulture is an umbrella species so that the work we do in improving the mountain habitat for the bearded vulture benefits other mountain wildlife too, such as black grouse, golden eagles and ibex,” said Tavares.

He believes the reintroduction project is helping other wider conservation and rewilding goals. “Bearded vultures are scavengers, they’re not predators, so they won’t kill cattle or game species such as chamois, so uniquely there are relatively few conflicts with people – unlike wolves or bears which are far more controversial,” he said.

The birds are scavengers so do not kill cattle or game species. Photograph: Hansruedi Weyrich

“Because bearded vultures are a neutral species, everyone works with you – so for example, we’ve been able to talk about banning the use of lead bullets with hunters. If we’d been working with wolves we wouldn’t even be able to sit in the same room as the hunters.”

The Alps, Europe’s biggest mountain range, have undergone intensive development in recent years from both the ski and hydroelectric power industries. The result is that one of the main threats facing bearded vultures is collisions with ski lift cables and power lines – accidents that kill one or two birds every year.

“We are working closely with ski resorts and power companies to fit visual deterrents on their cables to reduce this problem,” said Tavares.

Tavares is upbeat about the bird’s future and its value to the region. He says he realised its potential after the response of locals to the first reintroductions: “When I saw the enthusiasm of the local stakeholders when we released our first bearded vulture back into the Alps, I instantly realised that we had something very powerful.”