Scientific name : Gypaetus barbatus meridionalis Afrikaans : Baardaasvoël Zulu : uKhozilwentshebe Sotho : Ntsu
In former times the distribution of this magnificent raptor extended from the Cape of Good Hope, along the eastern mountain spine of Africa into north-west Africa, then through the Middle East and into Europe and central Asia. Now the only population left in the Southern Hemisphere resides in our isolated and rugged Maluti-Drakensberg highlands. This endangered African sub-species has suffered more than 30% decline in recent history and there are thought to be only between 125 and 155 pairs left.
BODY BASICS >>>>>>>>>>>>
Bearded Vultures are big shaggy, birds that look more like eagles than vultures (their Zulu name even translates as ‘eagle with a beard’). They are black in colour with pale heads and bellies. Their belly feathers, however, get stained a rusty brown colour by the iron-oxide found in the mountain rock on which they roost. Juvenile birds are completely dark and change colour gradually. Bearded vultures have a pale yellow eye, outlined in red and a black mask that extends into hair-like feathers on their lower jaw to make ‘the beard’ after which they are named. Ornithologists suggest that this beard has a tactile function cautioning the feeding bird from inserting its head too deep into a carcass and befouling its feathers.
They are well-adapted to their cold mountainous homes. Their broad, stiff overlapping contour feathers prevent the icy wind from penetrating the soft, insulating down underneath. Bearded vultures spend 80% of daylight hours soaring gracefully on the wing, their bare feet tucked in shaggy feathers to keep them warm. They weigh in at approximately 6kg, have long pointed wingspans extending 2.6m and extremely long, diamond-shaped tails.
Like all vultures they have a carrion diet, but Bearded Vultures are uniquely specialized, both physically and behaviourally, to live mostly on a remarkable diet of bones and bone-marrow. They have a very wide mouth and can swallow bones as long as 25cm, but accessing the nutritious bone marrow requires more work.
THE DROP ZONE >>>>>>>>>>>>>>>>
After other vulture species have cleaned the carcass, Bearded Vultures remove bones from the skeleton by cutting through ligaments with their sharp beaks. Smaller bones are eaten directly but bones that are too large to swallow need to be broken. To do this they fly off carrying these bones in their feet and then drop them very accurately from a height of about 60 metres onto open rock surfaces called ossuaries. They immediately descend and extract the exposed bone-marrow with their rough, scoop-like tongues. Some bones may only break after numerous drops. The energy content of this marrow diet is 15% higher than a meat diet, but it certainly takes a lot more effort to prepare the meal.
For the first four years of their life Bearded vultures live and scavenge alone. Then they choose a mate and together make large, untidy, stick nests lined with wool, hair, skin and other delightful debris. These nests are built in large potholes that have eroded into the side of cliff-faces. The pair alternate between a couple of nest sites every year. This practise is thought to increase cleanliness, as overused, befouled sites have higher parasite infestation.
Bearded vultures lay two eggs but, like the big eagles, only raise a single chick. The eggs are white in colour but soon the red oxide that stains the parents’ stomach feathers tints the shell red-brown as well. Both parent birds incubate and feed the chick, taking meat chunks and broken bones in their feet back to the nest, where they break off pieces for it to swallow. Chicks fledge at about 4 months and the vultures breed every year, despite their long breeding cycle.
Their populations are threatened by the fact that there is less food available to them because of better rural farming practices and thus less stock mortalities. Their feathers, skins and body parts are used for ceremonial and traditional medicine purposes. They also fall foul to traps and poisoned baits set out by farmers trying to eradicate stock killers, like jackal and feral dogs and are also vulnerable to electrocution on power-lines.
DID YOU KNOW??
• The Bearded Vulture used to be known as the Lammergeier, which in German means ‘lamb vulture’ and referred to what people thought were their lamb-catching tendencies. This inappropriate name has done these large scavenging birds a great disservice.
• In the early 1960’s scientists thought that the Bearded vulture might be extinct so undertook many unsuccessful expeditions to find them. Eventually, a Basotho elder led them to a nest site near Mokhotlong and they took their first nest photos.