The Bone-Eating Bearded Vulture Is Reclaiming Europe’s Skies

Obwaldera is late. In less than 48 hours, scientists are scheduled to release the three-month-old Bearded Vulture on a Swiss Alps mountainside, along with a second chick named Marco. Raised in different captive breeding centers, the birds were carefully chosen—based on their DNA—to join one of the most highly managed wildlife populations in Europe. The hope is that they will both survive to adulthood, find mates, and raise chicks of their own, helping to ensure the long-term survival of the continent’s rarest vulture. But while Marco arrived from Estonia without incident, Obwaldera and her two human escorts got hung up at the Austria-Switzerland border. They’re still several hours away, and the narrow window to prepare the young vulture to be set free is closing.

Scientists spent much of this warm morning in early June getting Marco ready at the Natur-und Tierpark Goldau, about 30 miles south of Zürich. They extracted a blood sample, outfitted him with a tiny transmitter to track his movements, banded both legs with identification cuffs, and bleached a unique pattern on his underfeathers to help observers identify him from the ground. Now Marco rests while the team counts the minutes waiting for Obwaldera to arrive. The longer the delay, the hotter it will be when it’s her turn to receive the accoutrements of a reintroduction program graduate, and the less time she’ll have to recover before being released. “It’s not something you really want to happen,” says Franziska Lörcher, a biologist who helps lead the Vulture Conservation Foundation’s (VCF) reintroduction and scientific program.

A lot is riding on Marco and Obwaldera’s release. Once common across mountains from western Spain to the Balkans, the formidable Bearded Vulture disappeared across almost all its European range more than a century ago. But after a decades-long conservation effort, the massive birds have begun to reclaim the Alps and other alpine slopes. The project is part of a long-term strategy to bring the species back across its full range in Europe, Africa, and Asia. Today, about 465 breeding pairs fly Europe’s skies, and in 2021 there were 44 fledglings, a record for the reintroduction program. “It’s one of the most successful conservation projects in Europe,” says VCF Director José Tavares.
 

But while the population soars toward recovery, it still faces obstacles. With so few birds compared to historic numbers, their gene pool is still dangerously limited, and the success or failure of each released individual makes a difference to the population’s health.

Finally, Obwaldera and her entourage arrive, and a team quickly gets to work. But during the preparations, the bird’s chest begins to rise and fall rapidly—too fast in Lörcher’s estimation. The team decides to break until it’s cooler, and later finishes up without further incident.

While the birds rest, the humans turn their attention to the remaining items on their long pre-release to-do list. In two days, hundreds of people will gather to celebrate two more Bearded Vultures joining the wild flock. Such a warm reception represents a remarkable shift. Until only a few decades ago, many locals viewed these majestic birds not as beloved wild neighbors but as menaces.

The Bearded Vulture is one of the world’s more unique birds. With a wingspan stretching nearly 10 feet, the largest bird of prey in the Alps cuts a majestic silhouette soaring above snow-laced granite peaks, the distinctive tuft of chin feathers it’s named for often visible from the ground. The bird’s all-brown plumage as a chick turns white along its head, neck, and chest as it matures. For reasons biologists still don’t understand, Europe’s adult Bearded Vultures dye themselves a reddish orange by taking dips in naturally-occurring iron oxide-rich waters.

The raptor’s most distinguishing feature, however, is its unusual diet. While most vultures scavenge carrion meat, Bearded Vultures generally eschew flesh. They are the only birds in the world that eat primarily bones, which they scavenge from the carcasses of sheep, cattle, deer, ibex, and other animals. First, a vulture will select a fresh and nutritious bone. If it’s roughly a foot or longer, the bird will enlist the help of gravity to break its meal into bite-sized pieces, lifting the bone into the air and dropping it onto rocks. The vulture’s highly acidic digestive system breaks down the hard substance, releasing nutrients and fat from the marrow.

The very features that make Bearded Vultures efficient bone-eaters—including flat feet and dull talons designed to help them walk around carrion to pluck out bones rather than tear into flesh—also make them poor predators. But misconceptions about the bird’s diet persisted for centuries and fueled its persecution. During the 19th and early 20th centuries, Europeans falsely believed that the birds attack livestock and even people—the species’ German common name, Lammergeier, means “lamb vulture.” Damaging propaganda often appeared in newspapers, novels, and textbooks, capturing the public imagination. One antique French poster features a man aiming a shotgun at an oversize, angry vulture while a dog nips at its tailfeathers. A passage in a natural history text from the 1800s reads: “He has an incredible muscle strength, so that he can with ease carry lambs, goats, even children in his claws from one mountain to another.”

To defend against the perceived threat, people shot and poisoned the birds in the Alps, the Pyrenees, and other areas. Many countries even offered a bounty, leading to the vulture’s precipitous decline. While a tiny population held on in the Pyrenees, the last Bearded Vulture in the Alps was shot in Italy’s Aosta Valley in 1913. The species fared just as poorly in other parts of Europe due to a combination of similar maltreatment and slower-burning threats, such as the decline of wild herbivores.

In 1978, a small group of biologists decided to return the species to its rightful place in the Alps. At the time, their success was far from certain, recalls reintroduction pioneer Hans Frey. During the previous decade biologists had reintroduced Griffon Vultures in France—the world’s first successful such effort for a large raptor—but that effort was less complex because it didn’t involve a captive-breeding program. The team also worried that there may not be enough good habitat and food to sustain a viable population. “It was a big question mark whether it would work,” says Frey.

The Bearded Vulture team collaborated with zoos that had birds that had successfully reproduced to create a small captive-breeding program. They also identified suitable release sites—rocky ledges for nesting in remote areas with ample food—in four national parks that were close enough for released birds to find each other. By 1986, the team reintroduced the first four captive-bred birds in a national park Austria’s Alps. One had to be brought back into captivity the next year after suffering from a frozen wing, but the others adapted well. Biologists released chicks in 1987 in France, and more reintroductions followed in Switzerland and Italy. In 1997, 11 years after the first release, a pair successfully bred and hatched a chick in the wild.

Today VCF oversees a captive-breeding network that involves 40 entities, including zoos, nonprofits, and government collaborators. To maintain the captive population, biologists keep at least the first four chicks of each breeding pair in captivity; their subsequent offspring are often released to the wild. Breeding facility employees play the role of parent for a few months, providing raw meat until the birds develop strong stomach acid and the ability to scavenge on their own. To prevent inbreeding, each bird is carefully matched to a release site to offer the best possible genetic boost to the small wild population. Chicks, like Marco and Obwaldera, are also released in pairs; while Bearded Vultures don’t live in groups, they are social and like company.

Between 1978 and 2016, biologists reared 488 young birds in captivity, allowing reintroductions to expand to other mountain ranges, including Andalucía in Spain, the Grands Causses in France, Sardinia, and Corsica. Today, about 88 percent of released birds survive their first year, and the number of wild-born vultures has risen steadily. “It’s been surprisingly successful, and all of us are very happy now,” Frey says.

Winning public enthusiasm for the reintroductions has been another crucial element in this success, Lörcher says—as important as getting the science right. Early on, biologists and conservationists met with farmers and other community members in the Alps to bust myths about the bird and began holding educational demonstrations. In the early 2000s, their blitz expanded to web cams and online resources. At age 11, Lörcher saw her first Bearded Vulture at a demonstration event, sparking an awe of the distinctive raptors that stayed with her.

All of these efforts improved public perception of the species, and the birds are, for the most part, no longer reviled. In the small villages near the Switzerland release site, where bell-adorned cattle and sheep graze impossibly green grasses, four residents speak readily of their support the reintroductions. “They were here before us,” says Claudia Gasser, who lives in Sachen and teaches religion at a local school. “This is their home.”

Marco and Obwaldera’s release day is equal parts conservation, education, and entertainment. More than 350 schoolchildren, locals, and officials show up at a local ski resort for a two-hour event that includes conservation talks and a show-and-tell with the avian guest stars.

Spread out across an alpine meadow, Lörcher and a colleague each hold a bird aloft as onlookers form circles around them. Outstretched phones capture the birds’ final moments as captives, and then they’re placed in wooden boxes and carried up a valley, a crowd tagging along. Leaving the public behind for the last steep leg, the team treks the birds up a switchback to a ledge where an artificial nest awaits and carefully place the chicks inside. After the crew leaves, a camera set on the nest will allow biologists and fans alike to observe as the birds prepare to fledge in the coming weeks. Biologists, also keeping watch from a lookout across a narrow valley, will deliver the birds raw meat until they can sustain themselves.

Now on their own, Marco and Obwaldera will face new tests. Farmers are reviving the use of poisons to protect livestock from rebounding wolves and bears, and vultures can die from feeding on tainted remains.  (VCF works with law enforcement to reduce poisonings in some areas). Wind turbines expanding into higher elevations also concerns conservationists: In a small wild population where each breeding pair produces only one fledgling per year, even a few fatal collisions could have a big impact.

Emerging diseases also pose a threat. Warmer temperatures have brought mosquitos that carry West Nile virus, which rarely kills the birds outright, but weakens their immune system, leaving them vulnerable to other dangers. Birds in the captive breeding facilities are especially susceptible (Initial results from vaccine trials begun in 2021 are promising). Biologists are also monitoring Bearded Vulture for avian flu. While none are known to have died from the illness, a recent deadly outbreak that has swept across the world has killed several Griffon Vultures in France and endangered California Condors in the United States.

The most pressing barrier to recovery, however, is low genetic diversity—and the inbreeding it can cause. The entire species numbers only a few thousand adults, and these largely live in isolated, mostly declining populations. In Morocco, for example, only 6 to 10 pairs remain. In southern Europe and the Mediterranean, the species still only occupies a small part of its former range.

In a bright spot, populations are now rising in six of nine European countries where the bird currently lives, and the team continues to plot reintroductions into new areas, such as the Balkans. Ultimately, connecting more of these isolated populations so that they interbreed will boost prospects of longer-term recovery across the continent, Lörcher says. Already, the team has spotted one bird that flew between the Pyrenees and the Alps. (Because vultures in the Pyrenees never went extinct, their population has greater genetic diversity, and intermixing helps create more robust Bearded Vulture populations in the Alps).  If all goes well, one day soon, Lörcher hopes, releases here in the Alps will no longer be needed.

Biologists even hope to bridge Europe’s population with isolated birds in northern Africa. It’s a long shot, Lörcher says, because Bearded Vultures don’t like crossing large bodies of water. An adventurous bird named Boni recently offered cause for optimism, however: In 2022, the one-year-old, the offspring of a pair reintroduced in Spain, flew across the Strait of Gibraltar to Morocco.

For now, the team will continue their genetic matchmaking. This year was a record season for captive-bred chicks—35 total—and more than 21 birds were released in Spain, France, Germany, and Switzerland. As for Obwaldera and Marco, they fledged and were spotted circling the skies together a few weeks after their release.

But neither of their stories played out exactly as planned. Although handlers go to great efforts to avoid vultures imprinting on people, in August the team had to recapture the young bird because he was showing an unhealthy curiosity in his new human neighbors—a first for the Alps reintroduction program. Marco will live out his life in captivity, where he’ll still contribute to his species’ recovery in the captive-breeding program.

Obwaldera, meanwhile, seems to be thriving in the wild and continues to explore new territory. But contrary to initial DNA test results, a later one showed that Obwaldera is male, not female. Luckily, Lörcher says, there are enough females around for him to find a mate. As the now free-flying bird—last spotted about 90 miles away from the release site—adapts to his new home, fans around the world are cheering him as they track his progress on the project’s web site. Everyone hopes he’s one of the lucky birds that beats the odds.