Bearded vulture
| Bearded vulture | ||||||||||||
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Bearded Vulture ( Gypaetus barbatus ) |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Gypaetus | ||||||||||||
| Storr , 1784 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Gypaetus barbatus | ||||||||||||
| ( Linnaeus , 1758) |
The bearded vulture ( Gypaetus barbatus ) or lammergeyer is a bird of prey from the hawk family (Accipitridae). It forms the only species of the genus of the same name ( Gypaetus ). Traditionally it belonged to the subfamily of the Old World Vultures (Aegypiinae), before it was placed in its own subfamily (Gypaetinae) with the Egyptian vulture and the palm vulture based on molecular genetic studies .
With a wingspan of up to 2.9 meters, the bearded vulture is one of the largest airborne birds in the world. Along with the black vulture, which is roughly the same size, it is the largest bird of prey in Europe and, with 225 to 250 breeding pairs, one of the rarest.
Surname
The bearded vulture was called the lammergeyer because of the mistaken belief that it would kill lambs - a name that has become common in English-speaking countries as the lammergeyer . Names such as bearded eagles or predatory eagles also indicate its external resemblance to an eagle . Goldgeier , Bart Falk , mountain vultures , leg breaker or Bonecrusher are other names that have been the vernacular of this vulture.
Appearance
Adult bearded vultures have high-contrast body plumage. The top is gray-black. The head, neck and the underside of the body are white to rusty red. Their wingspan is 2.30–2.83 m, their body length 94–125 cm, their weight 4.5–7 kg. Young bearded vultures are predominantly gray-black, after five to seven years the species is colored. Bearded vultures show only a very slight sexual dimorphism .
Conspicuous, bristle-like black feathers hang over the bearded vulture's beak. You gave this species its name. The eyes are surrounded by a red scleral ring; the intensity of the red reflects the mood of the bird. The more aroused he is, the brighter this scleral ring is. The irises of the eyes are yellow.
The bearded vulture has long, relatively narrow wings that are clearly pointed towards the end, which are kept hanging down slightly when gliding. The tail is long and wedge-shaped. Overall, it is significantly narrower-winged and longer-tailed than all other vultures and looks more like a giant falcon in its flight pattern . As an excellent sailor, he can use even the slightest updraft to patrol rock faces or over a mountain peak while gliding.
Distribution area
The bearded vulture has a disjoint distribution area today . It can be found in Africa as well as in the Pyrenees , some mountain regions of southern Europe, also in the Tauern , in the mountains of southwest and central Asia, Mongolia and central China. Two subspecies are described within this large distribution area:
- Gypaetus barbatus barbatus is the nominate form . It is native to the Atlas Mountains in Morocco , Algeria and Tunisia as well as the Pyrenees , Corsica and the Caucasus Mountains . It is also the subspecies found in Asia.
- G. b. meridionalis is the African subspecies of the bearded vulture. It is slightly smaller than the nominate shape and has short spring trousers and plain, light cheeks. This subspecies is found in Africa with around 15,000 individuals in northern Tanzania , in Kenya , Uganda , Ethiopia , Sudan , Lesotho and in southwestern Arabia .
habitat
Typical habitats of the bearded vulture are alpine and montane mountain regions above the tree line . These areas are characterized by large differences in altitude, steep rock faces, good thermals and updrafts. They must also have fresh water and so-called red bathing areas. Inaccessible rock niches are necessary for the bearded vultures to breed. It is also important for the bearded vulture that there is a population of predators such as wolf and lynx as well as large birds of prey such as golden eagles in its habitat. He needs them because he takes over part of the booty from them.
The altitude regions in which the Bearded Vulture reside correspond to altitudes between 1500 and 3000 meters in Europe. In the Himalayas they occur up to 7800 meters. In Ethiopia, on the other hand, you can see the bearded vulture at an altitude of 300 meters above sea level .
The area claimed by family groups or couples has a size between 100 and 400 square kilometers. During the winter months, the area that Bearded Vultures fly over while foraging becomes even larger. However, Bearded Vultures only behave aggressively towards their conspecifics and other birds of prey in the immediate vicinity of their nest . Bearded vultures are resident birds that stay in their breeding ground all year round.
Food and subsistence
Bones as a food niche
Bearded vultures live almost exclusively on carrion - the only exception to this are tortoises in the Mediterranean area . The bearded vulture carries tortoises into the air and, like bones, lets them fall from great heights. In Africa, it has also been observed eating the placenta of wild and farm animals. The bearded vulture lands in the middle of the herd and then approaches the remains of the birth on foot.
Its diet consists of 80% bones from fallen animals and carrion. Young animals are still dependent on muscle meat, adult animals can feed almost exclusively on bones. An adult animal needs between 250 and 400 grams of bone a day. Bearded vultures drop their bones onto rocks from a great height in order to chop them up and obtain pieces that are suitable for the mouth.
If a bearded vulture discovers a carcass, it first circles over it for a while. If it lands, it does so at a distance from the carcass and approaches it on foot. He keeps prey that he does not eat immediately in larger hiding places in clumps or resting and sleeping places.
By specializing in bones, the bearded vulture has found a food niche that no other animal can contend with. He therefore also waits patiently until other predators such as foxes , wolves , bears or other vultures have enjoyed the carcass. The spectacular distribution disputes that can be observed, for example, in the African savannah, when vultures between lions try to get to parts of the carcass, do not occur with bearded vultures. By specializing in bones, the bearded vulture has developed a nutrient-rich source of food. Bones contain an average of 12 percent protein , 16 percent fat , 23 percent minerals and 49 percent water. Bearded vultures drink frequently because of the low water content of their bones. They are therefore dependent on fresh water sources in their habitat and also take in snow to quench their thirst.
The techniques of bone-eating
Bearded vultures have an exceptionally large cleft mouth. Adult birds can swallow bones up to 18 centimeters long and 3 centimeters thick whole. However, even larger bones are crushed before eating. In contrast to other species of vulture, the bearded vulture has quite flexible grasping feet and pointed claws. Therefore, he is able to grab the bones, rise with them in the air and drop them from a height of 60 to 80 meters. Bearded vultures established in a territory regularly use so-called bone smiths , which are rock slabs with an area of around 30 square meters. The bearded vulture lets the bone fall onto these surfaces so that it breaks. Bearded vultures are stubborn and drop bones up to forty times before they finally break. The Spanish name of the bearded vulture Quebrantahuesos ("who breaks the bones") takes this up.
Bearded vultures are born with a tendency to drop bones. However, they only acquire technical skills over time. Very experienced birds only let go of the bone after they have started to dive.
The sufficiently crushed bone debris is swallowed and dissolved in the stomach by the vulture's strong stomach acid .
Reproduction
Bearded vultures are agile and skilful fliers and show this during their courtship game . The courtship game includes chases between partners, loops , flies on their backs, in which the birds occasionally grab each other's fangs and spin together to just above the ground. This alternates with flight phases in which they fly completely synchronously at a distance of a few meters.
Bearded vultures often build huge clumps in inaccessible rock niches. The construction of the nest begins in autumn. The eyries are used again and again by the bearded vultures who live in close partnerships. Older clumps can reach a width of three meters and a height of two meters. When building their nests, the bearded vultures process not only branches but also bones and pad the nest hollow with feathers and animal hair. Wherever you find them, you can also use rags and paper to cushion them. In the literature there is even a case where a prayer rug was used for padding.
Eggs are laid in late December or January, when particularly harsh weather prevails in their preferred habitats . Bearded vultures usually lay two eggs. The second egg follows about a week after the first. The incubation period is 52 to 58 days. The second hatching young bird is usually not able to prevail against the older young bird in the fight for the food. Therefore, he usually dies within a few days from neglect. In rare exceptional cases, the older young bird kills its weaker sibling ( cainism ). The young birds, which mostly hatch in March, are born when the snow melts and numerous animal carcasses from wild animals that perished in winter are exposed. During this time, bearded vultures find it easy to obtain food for the young bird. The nestling period is 110 to 120 days.
While adult bearded vultures are resident birds, young birds roam around. However, they only leave the mountains in exceptional cases. On her forays she protects, among other things, her youth clothing from the aggression of the territory owners. Adult birds tolerate birds in their youthful dress on their prey. Bearded vultures reach sexual maturity at the age of 5–7.
Bearded Vulture and Human
For a long time, the bearded vulture was called the lammergeyer because this bird was seen as a hunter of lambs and chamois and was even told that it would occasionally carry a child. After the middle of the 19th century, Friedrich von Tschudi still stated about this species:
“In 1854 there was still a woman living in Urnerland who was kidnapped by a lammergeyer as a child. In Hundwyl ( Appenzell ), such a daring robber carried a child away in front of his parents and neighbors. On the Silberalp ( Schwyz ) a vulture came across a herding boy sitting on a rock, immediately began to tear him to pieces and pushed him into the abyss before the herdsmen hurrying to drive him away ... "
While the bearded vulture still lived in a large part of the Alpine arc in the first half of the 19th century, it was completely wiped out in the Alps in less than a hundred years . With the increasing use of the mountain regions by humans, on the one hand, their food became increasingly scarce. At the same time he was subjected to rigorous hunting. The sovereigns even offered bonuses. The last birds were hunted in Switzerland in Visp in 1886 , in Austria in 1906 and in Italy in the Aosta Valley in 1913 . One last nest was destroyed.
Successful resettlement in the Alps
In the 1970s, resettlement in the Alps appeared possible, as there were again large numbers of wild ungulates that were considered as food for the bearded vulture. In addition, a new law came into force that protected the bearded vulture and prohibited the use of strychnine in bait. Inspired by breeding successes in the Innsbruck Alpine Zoo since 1973, an international group was formed with the aim of reintroducing the bearded vulture through reintroduction into the Alps.
In 1986 in the Rauris Krumltal ( Hohe Tauern National Park , Austria) an attempt was made to release young bearded vultures that had hatched in captivity. For this, about 10 weeks old, still flightless young animals were released in an artificial eyrie and fed until their first flight with about 4 months without human contact. After that, food was offered in the area until the young vultures could feed themselves. To this day (e.g. 2014 in East Tyrol's Debanttal ), young bearded vultures have been successfully released into the wild in the national park.
On June 8, 2018, the probably last release in the Hohe Tauern NP took place - due to success: young birds were left out in the Seebach valley, but national park rangers and their own bearded vulture keeper still look after the birds, which do not fledge until July or August . In Austria, 61 bearded vultures (216 across the Alps) have been released since 1986, 16 currently live in Austria, even if some have been shot. The birds have markings and transmitters that provide 3–4 years of location data that can be accessed on an updated map on the web. Experts and bird lovers have built an observation network and a lively community over the years.
Because of the success, further release sites were added in the years following 1986 in Haute-Savoie , the Vanoise and Mercantour National Parks ( France ), Stilfser Joch ( Italy ) and in the Swiss National Park (1991) and in the Maritime Alps (Italy). In autumn 2005 a total of 137 young bearded vultures were released, around 80 of which survived in the Alps.
Young vultures from captive breeding developed into independently viable individuals without any problems. The survival rate was higher than expected and is around 70 percent. The birds still find good living and breeding conditions in the Alps. The first attempt at breeding took place in 1997 in Haute-Savoie . Since then, the very fertile couple have successfully reared cubs four more times. By 2002 a total of 8 pairs had bred in the Alps, six of them successfully. The other pairs that found each other gave birth to another 16 young bearded vultures. In 2002 six young birds hatched in the Alps, three in Italy and three in France. In 2005 there were 27 bearded vultures hatched in the Alps. The first bird hatched in 1997 in Haute-Savoie is now sexually mature and the second generation will soon be able to nest. 25% of the approximately 100 bearded vultures currently living in the Alps come from free-range broods. The release is expected to expire in the next few years. The natural use of dead grazing animals by scavengers is to be promoted even more intensively than before.
More than 100 years after the bearded vulture was extinct in Switzerland, two pairs of bearded vultures brooded again in the Swiss Alps for the first time in 2007. For the first time in 122 years, a young bearded vulture hatched from an egg in the wild in the area of the Graubünden oven pass . The hatch presumably occurred between March 20 and 25, 2007. On July 31, 2007, one of the two boys fledged on the Ofen Pass and took his first sightseeing flight. In 2008 two young animals fledged (again on the Ofen Pass and for the first time in the Albula area ). 2014 was a record year for the resettlement project in Switzerland with ten wild-hatched cubs; in 2017 there were already 13 birds. In addition to the established sites in the Calfeisental , animals were recently released in the canton of Obwalden .
According to current information from the Swiss national ornithological station, there are currently around 100 bearded vultures living in the Alps. 50 different specimens have been observed in Switzerland, but these also come from other countries as they “roam” all over the Alps.
Accompanying measures for resettlement
Misunderstandings and misinformation about the way of life of the bearded vulture also contributed to the extermination of the bearded vulture in the Alps at the beginning of the 20th century. The resettlement attempts that began in the 1980s were therefore accompanied by extensive awareness-raising campaigns. Farmers and hunters in particular have been informed that the bearded vulture does not deserve its former name “lammergeyer” and is actually a bird that specializes in carrion. Measures that were implemented included involving farmers and hunters in observing the first abandoned birds. Both groups should be able to convince themselves that the bearded vulture only eats bones. One of the more unusual measures also included keeping rabbits , marmots and chickens in the bearded vulture enclosures in some breeding stations and zoos to demonstrate that bearded vultures do not attack live animals. Recently, however, there are some cases in Spain where vultures have attacked and killed live animals (freshly born calves, sheep), but mainly because they could not find enough carrion in their habitat .
As before, good ornithological literature also states that bearded vultures cause chamois and sheep to crash on mountain ridges by flying close to them.
The strictly protected birds are still shot down to this day. In 1997 a Swiss hunter who shot down a female important for the resettlement project was sentenced to 10 days probation and a fine of 20,000 Swiss francs . A number of other perpetrators who shot down bearded vultures illegally could not be caught. In the Pyrenees, poisoned baits are still being laid out, which are aimed specifically at bearded vultures. Bearded vultures, however, also eat the poison bait that is laid out for poaching dogs, wolves or foxes and die on it. Nests are also still gutted in order to sell the eggs at the collector's market.
Protection project in Crete
A protection and education project within the framework of the EU program LIFE between 1998 and 2006 succeeded in stabilizing the population in Crete to six breeding pairs. The work concentrated on the Asterousia Mountains (south of the Messara plain ) and the mountain Agios Dikaios (in the far west), where a nature trail and an observation station were set up. Another breeding pair can be found in Samaria National Park ; Griffon vultures are much more common there .
literature
- Robert Hofrichter: The return of the wild animals - wolf, vulture, elk & Co. Leopold Stocker Verlag , Graz 2005, ISBN 3-7020-1059-9 .
- Benny Génsbol, Walther Thiede: Birds of prey - All European species, identifiers, flight images, biology, distribution, endangerment, population development. BLV Verlag, Munich 2004, ISBN 3-405-16641-1 .
Web links
- Project on the reintroduction of bearded vultures in the Alps
- Film and photo work on the subject of "Bearded Vultures in the Alps".
- Bearded vulture in protected areas in East Tyrol: In the valley of the bone breakers
- LIFE Gypaetus 2002. Natural History Museum of Crete, archived from the original on June 16, 2009 ; Retrieved on August 14, 2012 (English, Bearded Vulture Protection in Crete).
- Gypaetus barbatus in the endangered Red List species the IUCN 2012. Posted by: BirdLife International, 2012. Accessed August 15, 2012th
- Videos, photos and sound recordings of Gypaetus barbatus in the Internet Bird Collection
- Recordings from the great outdoors at www.fokus-natur.de
- Photos of the bearded vulture in the Pyrenees on www.naturlichter.de
swell
- ↑ Probably the last bearded vulture release orf.at, June 8, 2018, accessed June 8, 2018.
