Bearded Vulture - the bird name | field characters | figures | bones | coloured plumage | cainism | marks | systematics

Bearded Vulture Interreg, July 2000 Picture ©: Archiv Nationalpark Stilfserjoch - Klaus Bliem

A Bearded Vulture does not look like a typical vulture. It is often mistaken for a Golden Eagle, which lives in the same habitat.

Adult: large raptor (a bit larger than the Golden Eagle), long diamond-shaped tail, wings and tail dark, head and underparts light-rufous, black bristles hang at the base of the beak, conspicuous red circle around the eyes.

Immature: same size as adult, dark from head to tail with some light patches.

The vultures feed mainly on carrion. The Bearded Vulture has even a more limited diet: it eats chiefly bleached bones.- These are by no means the worst parts of animal carcasses: A bone may contain up to 12% proteins, 16% fat and some important minerals. This remarkable habitat has yet another advantage: bones are inedible to any other animals thus the Bearded Vulture has no competitors for its food. Its gastric acids are capable of dissolving even large bones.

Bones up to the size of the vertebra of a cattle may be swallowed whole by a Bearded Vulture. Larger bones are taken in the feet to "ossuaries" which are traditionally used plates of rock where the birds drop the bones from heights of 50 to 80 meters until they brake into small bits.

The white colour of neck and underparts of captive birds as opposed to rufous in wild ones has remained unexplained for many years, until someone discovered that wild birds deliberately put iron oxide on their plumage. When captive birds were provided with iron-rich water they started to bathe in it as they do in the wild and got a coloured plumage.

Bearded Vultures usually lay two eggs, but normally only one chick fledges. The eggs are laid at an interval of about a week. Thus the second chick hatches much later and is smaller than the first one. Young Bearded Vultures are very aggressive, and the older bird kills the younger one during the first weeks after hatching. The second egg is a biological reserve in case anything happens to the first. The behaviour of the older of the two young birds is called cainism after the first fratricide in human history. Thus cainism is very useful, since there would not be enough food for two nestlings.

For the reintroduction project it is important to know each individual bird which has been released. For that purpose they are individually marked by the bleaching of certain feathers of the wing or the tail. This mark is visible for about two years, until the first moult, when the feathers are replaced by new ones. People who have been watching the birds carefully for a long time are able to recognise even older birds by their behaviour.

Bearded vultures belong to the order of birds of prey. However, within this order the systematic organization is still disputed. Here, we use the systematics of Swiss Wildlife Information Service (SWIS).