What's in a Name?
Often referred to as a lammergeier (German for “lamb vulture”), this bird was almost misunderstood into extinction. Its intimidating size and lofty residences have earned it few predators but many enemies. Throughout history, people have blamed this imposing (almost a metre-tall) raptor for carrying off livestock and even children. This is disputable, as the birds are obligate scavengers and not known to be hostile toward (living) humans.
It has even been charged with the murder of the ancient Greek dramatist Aeschylus, who is said to have perished after a famished bearded vulture mistook his bald head for a rock and dropped a tortoise on it.
Common name
The bird's common name, the bearded vulture, refers to its characteristic tuft of black feathers under the beak. Other names include baardaasvoël (Afrikaans) and uKhozilwentshebe (isiZulu).
Taxonomic name
Gypaetus barbatus meridionalis – “bearded vulture from the south”
Appearance
At between 5-8 kg, this bird is undoubtedly one of considerable size. The adults have a dark grey-black appearance, with a slightly darker tail and lighter shaft streaks. The face has a distinctive look, with a thick black band around the eyes separating each side and long, broad, black bristles resembling a beard at the base of the bill. The forehead is cream-coloured, while the rest of the head is golden yellow, transitioning into a rusty orange hue on the neck and abdomen. In contrast, juveniles display a significantly different colouration, typically characterised by a mottled black-brown and cream appearance that gradually changes to the adult plumage as they mature.
However, what catches the attention most are the bird's striking red-rimmed eyes, a feature shared only with some parrots, and a long wedge-shaped tail. It is worth noting that, unlike most vultures, bearded vultures have a fully feathered neck and legs and lack an entirely bald head. The trait of feathered legs, usually found in Southern African eagles such as the African Fish Eagle, Martial Eagle, and Black (Verreaux's) Eagle, is also present in bearded vultures.
The reddish-brown colouration of their plumage is caused by dust bathing in oxide-rich soil. The birds' red-rimmed eyes are surrounded by a red scleral ring that fills with blood and functions in the vultures' threat display.
Current
Historical
Distribution & Habitat
A century ago, the majestic raptor had a vast home range that stretched from the Cape of Good Hope through the Southern Great Escarpment of the Eastern Cape and into South Africa's Maloti-Drakensberg Mountain Range, as well as throughout the Lesotho highlands.
However, today, the bearded vulture's range is severely restricted to the high altitudes of the eastern Maloti-Drakensberg Escarpment and surrounding foothills. These magnificent birds are rarely found below 1,000m above sea level and have even been sighted soaring at an altitude of 7,500m.
Bearded vultures thrive in wide open, mountainous terrain and typically establish their nests in remote areas with cliffs, precipices, or gorges overlooking fields and valleys populated with prey animals and their predators.
Breeding
Bearded vultures reach sexual maturity at 5 to 7 years, which is relatively late considering their average lifespan of 21.4 years. From May to June, the female lays one or two eggs in a nest typically about one metre wide during their egg-laying period. These nests are usually located in potholes or shallow caves on cliffs. The second egg is a backup if the first one fails to hatch. Asynchronous hatching is common in bearded vultures, with one egg hatching well before the other.
Over the breeding season, the nest gradually expands to around 2 metres in width. The eggs typically hatch after a period of about 60 days, and the hatchlings spend up to 130 days in the nest before they are able to fly. Due to their dependence on their parents for almost two years, bearded vultures breed every other year.
In most cases, the first chick to hatch is larger, and more dominant, than the second chick. Bearded vulture parents often exhibit a preference for the first chick and may only feed it or, in some cases, the stronger chick may harass the weaker chick in the early days of life and prevent it from accessing food, ultimately leading to its death.
Like many large raptors, bearded vultures practise this evolutionary 'cainism' (derived from the biblical story of Cain and Abel) in which the first-born chick kills its sibling to secure its own survival.
Diet
This remarkable scavenger has a highly specialised diet, consisting mainly of bone and bone marrow, which accounts for a whopping 85 to 90% of its food intake. Interestingly, the bird's stomach acid boasts an impressively low pH of approximately 1, which enables it to digest dense bone material in less than a day. It is the only known bird species that specialises in osteophagia or the consumption of bone.
The bird has developed a unique technique to access the nutrient-rich marrow within bones, essential to its diet. Large bones, which cannot be swallowed whole, are transported up to 30 metres high and dropped onto rocks or other hard surfaces, known as ossuaries. This process fractures the bones into smaller pieces, facilitating the bird's access to the marrow. This particular behaviour is infamously associated with the extraordinary end of Aeschylus, the ancient Greek playwright. According to legend, his death occurred when he was struck by a tortoise dropped by a northern bearded vulture.
Ecological Importance
Vultures play a critical role in maintaining the ecological balance by scavenging and consuming carrion, including diseased animals. These raptors are essential in limiting the spread of diseases, such as anthrax and rabies, as they can consume infected carcasses without getting sick. The value of all vultures in containing disease is immeasurable, as they prevent the spread of harmful pathogens and reduce the risk of outbreaks in both wildlife and domestic animal populations.
