Bone breakers
The lammergeier became extinct in Spain’s Picos de Europa mountains 60 years ago. Now, thanks to some ingenious parenting, this bone-gulping vulture is resurgent in far northern Spain. Paul Bloomfield reports.
Lammergeiers are back in Spain’s Picos de Europa
Broad-winged shadows circled overhead, one above another, above another – after 10, I lost count. On a searing June afternoon, the cerulean skies over the Cares Gorge were as congested as Heathrow during an air-traffic control meltdown, but these were vultures, not 747s, wheeling on high. I trained my binoculars on the cruising birds, hoping to spy the diamond-wedge tail of a lammergeier among the soaring griffons. In theory, it should be easy to identify this most distinctive of raptors. In theory.
“Even without making out its tail, you should be able to distinguish its flight,” observed Carmen Calero, biologist with the Fundación para la Conservación del Quebrantahuesos (FCQ), as we hiked along northern Spain’s most dramatic canyon. “Rather than circling slowly like a griffon, the lammergeier tends to fly along the rock walls; it’s more agile, its silhouette is more slender. So, if you’re familiar with it, you can normally identify one from afar...” Then she gave a wry smile… “normally.” In fact, there are many species with which to mistake them here in the Cares Gorge, which slices through the spectacular limestone Picos de Europa mountains 20km inland from the Bay of Biscay. And today, the lammergeiers were playing hard to get. Even the experienced eyes of Carmen and local guide Diego Martín failed to spy any among the griffons. Up close, there’s no mistaking the lammergeier for anything else, even its nearest relative, the Egyptian
vulture. The pale underparts and neck of this
DARK PATCHES ON ITS FACE STREAM LIKE MASCARA FROM RED EYE RINGS, ENDING BELOW THE BILL IN A TUFTY ‘BEARD’.
enormous raptor – a female’s dark-plumed wings span up to 3m – develop a rusty hue from wallowing in iron oxide-rich soil. Most striking is the characteristic from which it takes its specific name Gypaetus barbatus, ‘vulture-eagle with beard’. Dark patches on its face stream like mascara from red sclerotic eye rings, ending below the bill in a tufty ‘beard’ – hence its English name: bearded vulture.
The more-romantic ‘lammergeier’, or lamb’s vulture, was coined in German because of the mistaken archaic belief that the bird snatches lambs, even children. More accurate is the Spanish quebrantahuesos, ‘breaker of bones’, because the adult lammergeier is the only known vertebrate whose diet is almost exclusively bone. It feeds mainly on ungulates – here in Spain that’s chamois, sheep, domesticated and feral goats – swallowing smaller bones whole, and dropping bigger ones onto rocks to smash them into 20–25cm chunks.
BONE BREAKERS
The lammergeier’s singular diet was one reason we were scouring the gorge. “See the rock pile beneath the avalanche chute opposite?” Diego pointed to the bottom of a scree slope. “We call that a rompedero –a bone-smashing spot.” Powerful acid and enzymes in the bird’s digestive system process ossein, the collagen-based organic component of bone. Such a niche diet offers several advantages. “You might see huge numbers of griffon vultures squabbling over the meat on a carcass,” observed Diego. “But the lammergeier can conserve its energy and avoid conflict, sitting back and waiting till the others have finished the meat.” Fresh bones are best, scraps of meat providing added nourishment, but because a protective sheath around bone protects nutrients, even year-old bones provide a good meal.
Bones, rocks to break them on, cliffs to nest in: these are the three things lammergeiers need. Unsurprisingly, the species is widely scattered, with populations in north, east and southern Africa (the largest in Ethiopia), and across Asia from Turkey and the Caucasus through the Himalayas. However, its IUCN Near Threatened status reflects a global estimate of fewer than 7,000 mature individuals.
In Europe, the situation is acute, populations decimated last century by hunting and, more recently, poisoning. The last lammergeier in the Alps was shot in the early 20th century, though areas of France, Switzerland, Austria and Italy have been artificially repopulated. In Spain, hunting was promoted by Franco’s government, and in the 1950s meat baited with strychnine to kill wolves and foxes devastated lammergeier and griffon numbers. The last known lammergeier in the Picos died that decade, around the same time that the wolf was extirpated.
Both wolf and lammergeier are now back in the Picos – the latter’s return thanks to a groundbreaking project established by the FCQ. This NGO was founded in 1995 to protect the bird’s last viable reservoir population in the Pyrenees, where they now number 300–400. Recent studies led by vulture specialist Antoni Margalida found that though mated pairs use a relatively small home range, typically around 50km2, young birds range vast distances in search of territory and mates. And when sightings from the past 30 years were mapped, the research revealed a clear corridor of movement between the Pyrenees and Picos de Europa.
The Picos provide ideal territory. There’s ample nesting habitat and food, and the Picos de Europa National Park enhances protection. Despite the attractive habitat, though, if incoming birds can’t find potential mates they won’t settle here. So, in 2002 the FCQ launched a reintroduction project to establish an anchor population. The first birds were released in 2010 and, with the latest release of four youngsters in July 2017, the reintroduced population now numbers 14 (three having died since release).
PUPPET PARENTING
Somewhat controversially, these birds were sourced not from captive-bred stock but by hatching eggs retrieved from ‘problem’ nests in the Pyrenees – those with a history of minimal or no breeding success. Thesehese are incubated in a breeding centre in the Pyrenees an nd, once hatched, raised using a novel technique based ono one developed for California condors. Extinct in the wild since 1987, captivebred condors were nurtured by puppet ‘parents’ before release. Carmen, whose hand has occupied one such lammergeier puppet, explained more.
“Lammergeiers are dedicated parent ts. Mother and father alternate incubating and raising g offspring – the chick is never left unattended. We dod the same.” From the first few days after hatching ini February or March, Carmen operates an incredib bly detailed and lifelike latex puppet head from beh hind a black curtain, never speaking to avoid anya risk of the chicks imprinting on humans. Long hours of practice enabled her to mimic the movements of adult birds feeding hatchlings with a 90 per cent meat diet, gradually increasing the e proportion of bone.
After a couple of weeks a chick begins to interact with the puppet as it would a real parent. About 40 days later it’s moved to an open-sided cage at a hacking site in the Pyrenees, where it can see wild birds. Then, in late June or early July, perhaps three weeks before it’s ready to fledge aged about 100 days, it’s transferred to the release site in the Picos, above a feeding station. Once the cage is opened it will hop about for a few days before taking off.
Two days after our Cares hike, I joined field technician José Carlos Gonzalez on his weekly trip to top up the feeding station above Covadonga, in the national park’s lofty north-west. Omens for a lammergeier encounter were poor as our truck chugged through a dense peasouper. “They won’t fly in this cloud,” José sighed. “The feeding station isn’t maintained to provide nutrition for lammergeiers,” he explained. “There’s plenty of food for them in the Picos. It’s really a training tool. The food attracts griffon vultures, and young lammergeiers learn to look for them to identify the location of fresh carcasses.” When vision is limited to just a few metres, as it was that murky Friday, they simply sit it out.
On arrival, José unlocked the gates and rolled two hefty blue barrels offf the flatbed. The slope below resembled the aftermath of a particularly gruesome battle, scattered withh bloody bones. Soon it looked (and smelled) much worse, as José tipped out 100kg of sheep offal, accompanied byb a repulsive flabby sloshing like a punctured waterbed. That was followed by a similar volume of bones. Thhe stench was unbelievable, and I was happy to retreat to a viewing point well above the gory banquet.
HOURS OF PRACTICE ENABLED CARMEN TO MIMIC THE MOVEMENTS OF ADULT BIRDS FROM BEHIND A BLACK CURTAIN.
The cloud showed no signs of lifting, though. Still José refused to admit defeat, retrieving his radio telemetry kit and a laminated sheet identifying 11 birds and the frequencies of their tags. The idea of tagging such a huge talon-equipped bird seemed hazardous, verging on suicidal. But no. “Ringing or tagging griffons – now, that’s scary,” José chuckled. “But lammergeiers are quite docile; once you’ve got one it won’t nip or scratch.”
José adjusted the dial and swept his antenna above his head, searching in turn for named lammergeier: Atliano, Esperanza, Vitorina. Finally, a series of blips raised hopes: Escudero, lurking within 2km of our position. So close, yet still hidden by the murk. But his story reinforces the FCQ’s faith in their wild egg retrieval process. “Escudero’s parents tried to breed for 23 years, but nested near a popular climbing spot. Each year they were disturbed, and each year their nest failed. Escudero, released in 2016, was the first of their chicks to survive.”
It was a reminder that in lammergeiers, which can live 50 years in captivity, breeding is neither easy nor quick. Females, fertile from about seven years of age, are notoriously picky. Even having paired, the first few breeding attempts usually fail. That was the case here. In 2017, the first lammergeier egg in the Picos for over 60 years was laid in the Cares Gorge by seven-year-old Deva. The nest was flooded and failed. Yet it’s a sign that the project is achieving its core philopatric aim of encouraging vultures from elsewhere to remain and establish a viable breeding population: Deva’s mate, Casanova, is a wild bird that arrived independently from the Pyrenees.
It’s a point reiterated by Gerardo Báguera, the project’s director. “We’re not aiming to create a new population just through releasing birds, but by persuading incomers to stay. We do half of the work – the other half is natural.”
This is a long-term project, he added. “Creating a population that can survive without human conservation intervention, starting from zero, of a species that first breed successfully at nine, 10 years old – probably 30 years is a realistic timescale to see multiple couples breeding.”
As with birdwatching, patience is a virtue in conservation – and there’s reason to hope that it will be rewarded in the Picos.