Raptor Conservation, South Africa's Vultures
Vultures are a big characteristic and important part of Africa’s ecosystems. As scavengers, they play an important role in preventing the spread of disease by quickly disposing of decomposing carcasses laying in the environment.
Recent decades have seen an alarming decline in Vulture populations throughout Africa, even here in South Africa. Three of South Africa’s eight vulture species are now regarded as globally critically endangered.
#01. Cape Vulture
Cape vultures live together in large colonies, favouring layered sandstone and quartzite rock ledges as nesting spots and tell-tale fecal white-washed cliff sides make it easy to identify where Cape vultures are nesting. As their name would suggest, Cape vultures were once a common sight in the Western Cape, with colonies nesting on the cliff-sides of Cape Town’s Table Mountain, but as their numbers have dwindled, they have moved to the hilly terrain in the east of the country.
In the early mornings, vultures need the air currents found along cliff-sides to lift them into the air, but later in the day as the air heats and creates thermals, they can literally soar for hours with little effort as they scan the surroundings for food with eyesight eight times sharper than human 20/20 vision. Although they are scavengers and will eat rotting meat if they need to, vultures prefer their food fresh and as soon as a carcass is spotted, will descend rapidly to start feasting, generally getting to the carcass before ground scavengers can. A flock of vultures feeding is a noisy occasion, with a fair amount of squabbling as they rapidly strip a carcass, storing the meal in their crops to digest later or regurgitate for chicks.
As Cape vultures (Gyps coprotheres) typically lay only one egg each year, their slow reproduction rate is a contributing factor in declining numbers. Moreover, scientists have noted that there is a prevalence of metabolic bone disease among Cape vulture chicks, likely caused by insufficient calcium intake. This is possibly due to fewer mammal predators such as lions and hyenas which would break up carcass bones with their strong jaws, thereby creating bone fragments which adult vultures would take to their chicks. Chicks suffering from calcium deficiency are unable to fly, falling to their deaths when they try to leave the nest. It is estimated that fewer than 50 percent of vulture chicks survive their first year of life.
Some measures being implemented to help vultures survive include educating the public about the important role they play in the ecology by cleaning up carcasses, and dispelling the myth that vultures are a threat to livestock. Although they are classed as birds of prey, vultures are not equipped to kill animals, particularly healthy animals. Feeding stations with crushed bones are being made available in some areas to address the calcium deficiency issue.
#02. Hooded Vulture
These have historically been one of the most abundant vultures species throughout Africa, especially in West Africa, but data and observations of varying coverage and quality from various parts of its range suggest it is undergoing a very rapid decline in its global population. Within South Africa and Eswatini there are estimated to be only 100-200 mature individuals. Most are now concentrated around the Greater Kruger National Park.
The Hooded Vulture is a lovely, relatively petite vulture. Overall, it is a dark chocolatey brown color, with a white "collar" sometimes visible around its neck. True to its name, the hooded vulture has a small patch of downy feathers that runs along the back of its neck to the crown of its head, making it look like it is wearing a fluffy, cream-colored hood! It is has dark eyes and a long, narrow bill. Its face is devoid of feathers and its bare skin is normally white. However, when the vulture gets agitated or anxious, the white face flushes to a light pink or red - making it look as if it were blushing.
Like so many vulture species, the Hooded Vulture is often seen soaring high in the sky or gathered singly or in small groups at an animal carcass, garbage dump or slaughterhouse.
Many people mistakenly believe that vultures are dirty animals because of their steady diet of dead animals. However, the exact opposite is true. Vultures enjoy bathing and can spend quite a bit of time around watering holes. And speaking of bathing, vultures also spend time sunbathing, or sunning, as well. It helps them keep their feathers healthy and clean.
Scientists believe that when birds sun, this actually helps rid their feathers of unwanted and dangerous parasites. These parasites like to hide deep in a bird's feathers. Exposing them to sunlight, and the related heat, causes the parasites to move around, making it easier for the birds to pick off the parasites when they clean, or preen, their feathers.
#03. Bearded Vulture
The Bearded Vulture is a spectacular sight and plays a role in generating tourism revenue. Apart from its aesthetic value, the Bearded Vulture also has spiritual and cultural values in that they have played a role in many cultures over the centuries, for example ancient Egyptians, Buddhists. Bearded Vultures are an important part of the natural ecosystem and national heritage that need to be protected for future generations.
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 color with pale heads and bellies. Their belly feathers, however, get stained a rusty brown color by the iron-oxide found in the mountain rock on which they roost. Juvenile birds are completely dark and change color 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.
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 specialised, 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 reasons for the decline of Africa’s vultures are numerous and complex. Poachers kill great numbers of vultures by intentionally lacing poached animal carcasses with poison. Vultures are also vulnerable to secondary poisoning by the veterinary drug diclofenac, or unintentional poisoning through the ingestion of fragments of lead ammunition. Other threats include electrocution and/or collisions with power infrastructure, declining food availability, habitat loss and harvesting for belief-based use.
We hope that conservation efforts continue to bare fruit, and are able to rejuvenate these exciting and iconic bird species. Join us here in the Kruger National Park where there is always a good possibility of spotting these raptors circling the skies above.