Colours of Wildlife: Bearded Vulture
Created | Updated Oct 27, 2019
Bearded Vulture
Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"
Here you have a portrait of the Bearded Vulture, Gypaetus barbatus. The scientific name means 'bearded vulture-eagle'. It is indeed a very eagle-like vulture, or alternatively a vulture-like eagle. It is not closely related to other vultures, except for the Egyptian and Palm-nut Vultures (to be featured here soon) with which it is grouped in a sub-family of the Eagle, Hawk and Vulture Family. It is also known as a Lammergeier, which comes from the German for 'lamb eagle/vulture'. This refers to its supposed habit of driving lambs off the edges of cliffs and then feeding on their corpses. If this happens, it certainly doesn't happen a lot, but bearded vultures have been seen doing this with hyraxes and small mountain antelopes: either catching them and then dropping them from a height to their deaths, or driving them off precipices.
Dem Bones …
The main feeding strategy of bearded vultures is something quite different and special. An oldish name sometimes used for this bird is 'Ossifrage', coming from the Latin 'ossifragus', meaning bone-breaking ('os'=bone; 'frangere' = to break). In Spanish this becomes 'Quebrantahuesos' = '(the one) that breaks bones'. These names hit on the Lammergeiers own uniqueness: it is not just any old scavenger, but one specialised to feed on bones. It is the only species of bird to almost completely subsist on a diet of dead, dry bones.
The bearded vulture is very much adapted to its peculiar way of life. It is a huge bird of prey, reaching a length from beak to tail of 110 cm (about 43") with a wingspan of 263-282 cm (8'4"-9'3"). It can weigh up to 6.25 kg/14 lbs. It has long, pointed wings and a relatively long, wedge-shaped, sometimes described as diamond shaped, tail. In the adult bird, the wings and tail are slaty-black above as well as below. The wing coverts and scapulars – the shoulder coverts – have white shafts, showing up as thin white lines on the blackish wings. The neck, breast, belly and undertail coverts vary from yellowish to rusty-red. This colouration actually comes not from the feathers themselves, which are white, but is a kind of cosmetic 'stain' acquired from reddish rock or soil! It is apparently not exactly known how the feathers 'pick up' and retain this colouring, and exactly where or how, but it is probably from reddish iron-oxides (rust, actually) either in the caves where they roost and sleep, or from soil in which they dust-bathe, or from dissolved oxides in pools in which they drink and bathe.
The exact tint of the body-feathers of the bearded vulture therefore varies dependent on local soils, rocks and the behaviour of the individual bird. However, most of the time the feathers of the head remain white. This forms a contrast with the black "bandit's mask" of short, stiff feathers surrounding the eye. These black feathers also extend over the base of the bill and down to the chin where they are lengthened into a forwards-pointing tuft or 'beard'. This unique structure indeed gives the bearded vulture its name. The function of this beard is not known. It might have a tactile function, like the whiskers of mammals, and might be involved when it feeds on marrow-bones. The bearded vulture's eye is a pale yellow, surrounded by a red sclerotic ring, standing out prominently from its black 'bandit-mask'. The ring 'blushes' to a deeper red when the bird gets excited. The large, shaggy feathers on their bodies protect them from the cold and frequent rains in their high mountain haunts. When a bird ruffles its feathers, the rattle can be heard 30 m away!
The immature bearded vulture differs from the adult in being almost uniformly blackish or dark brown, with a black head and breast. It already sports the diagnostic black beard by the time that it can fly. Its body colour gradually lightens to the rufous-brown of the adult. Full adult plumage is only achieved after six to seven years!
Where other vultures soar and circle over plains looking for carrion, the bearded vulture is more likely to be found patrolling a cliff face. Spotting a carcass, it might feed on meat, if any is left – it often doesn't mess with other vulture species, waiting for them to finish first – but if only the bones are left – still good! Small or mid-sized bones are swallowed whole; only the longest bones such as thigh bones need to be broken into smaller pieces. And this the vulture does with finesse. It makes use of the rock sheets and slabs and outcrops of the mountains, dropping the bones from a height of 30-40 m or more to shatter on them. This sometimes entails several attempts.
In its territory, a bearded vulture might have a particular favourite 'anvil' for breaking its bones (that is to say, the ones it feeds on). This is recognizable by the many small bone fragments surrounding it. Bearded vultures have great accuracy, the 'anvil' often being quite a small target to hit from a height of thirty yards or more. A story, perhaps apocryphal, says that the Greek poet Aeschylus was killed when a bearded vulture mistook his bald head for a rock and dropped a tortoise on it!
Bones may not seem to be very nutritious. But bone itself does contain some protein along with minerals like calcium, magnesium and phosphorus. And the marrow in the bones are rich in more proteins as well as fats. Any animal high in the mountains, killed or dead of natural causes, will be scavenged by other vultures or ravens, but the bones will be left, and with few or no hyenas around, will be all for the bearded vultures. They can make quite a good living off it.
The main range of bearded vultures stretches over the high mountain ranges of Europe, Asia, and Africa: From the Atlas and Pyrenees mountains of Morrocco, Spain and France in the West, across the Alps, and the Balkans to the Anatolian mountains of Turkey. From there it goes east to the Caucasus and their Central Asian stronghold in the Hindu Kush, the Himalayas, Tien Shan and the Altai, and south through Egypt to the mountains of southern Yemen, the Ethiopian Highlands, and the ranges along the Rift Valley in Kenya and Tanzania with a further outpost in the high Drakensberg of South Africa and Lesotho.
In these mountain regions, bearded vultures have special requirements. They usually occur at altitudes over 1000 m … over 1 800 m in Africa. This habitat is generally covered by sub-alpine vegetation, without large trees, so that carcasses on the ground will be clearly visible. These regions must also be free of snow in winter or spring. Suitable carcasses would be those of domestic or wild hoofed mammals. Bearded vultures do in fact derive some benefit from human livestock raising in some regions, especially when tolerated by humans and under ‘primitive’ pastoral conditions. They will feed off human garbage dumps where tolerated. But where intensive stock farming takes place, they are usually persecuted: shot, trapped, poisoned. For these reasons, they have in recent years vanished from much suitable mountain habitat, such as in the European Alps and some of the mountains of the Cape Province of South Africa.
Apart from food, bearded vultures need suitable roosting and nesting areas. They prefer caves or overhangs surrounded by high cliffs, to give them safety from predators. They have a habit of shuffling backwards as deep as possible into cliffs and recesses, where it is warmer and out of the wind and rain; in captivity, they will crawl into any suitably large container provided.
Situated well back in such recesses, bearded vulture nests are big and bulky, up to 2 m in diameter, made mainly of sticks, but lined with animal wool and hair and sometimes stuff picked up from rubbish dumps. The female lays one or two eggs, but invariably only a single chick is raised. Both parents feed it, by bringing meat to the nest and tearing small strips off it, or regurgitating food to the chick mouth-to-mouth. The chick fledges at the age of about 110 days, but are cared for by the parents for a few more months. It probably needs some time to learn the proper bone-breaking strategy from them.
Like other vultures, bearded vultures are endangered. The main reason is poisoning: they feed on carcasses humans poison and leave out to destroy jackals, leopards and other predators. The vultures die as a side effect. Furthermore, humans who suspect them of killing lambs, will trap or shoot them. They also tend, also like other vultures, to collide with electricity lines and pylons. On the positive side, they have benefited from 'vulture restaurants' where safe meat and bones are left out for them to feed on. Their long-term survival depends on conservation and education projects, such as teaching people from the communities where they occur about their value, eliminating the use of poisons, and making sure human developments are harmonious with their needs.
