White-headed Vulture(Trigonoceps occipitalis)
The white-headed vulture is a medium-sized vulture, 72–85 cm in length and with a wingspan of 207–230 cm. Females have an average weight of 4.7 kg, while males are generally lighter at 4 kg or less. This species is unique among African vultures as it shows a degree of reversed sexual dimorphism, where females are somewhat larger than males. It has a pink beak and a white crest, and the featherless areas on its head are pale. It has dark brown upper parts and black tail feathers.
The feathers on its lower parts and legs are white, giving it its diagnostic image from below. These vultures are easily distinguishable from all other vulture species as the plumage exhibits a strong contrast between black and white. Individual white-headed vultures can also be reliably identified based on a unique pattern in their median wing coverts.
Habitat
The white-headed vulture is widely spread throughout sub-Saharan Africa, occurring from Senegal and Gambia east to Somalia and south to South Africaand Swaziland. It is locally uncommon to common. The species prefers mixed, dry woodland at low altitudes. It occurs at elevations of up to 4,000 m in Ethiopia, perhaps 3,000 m in Kenya, and can be found in thorny Acacia-dominated landscape in Botswana. It generally avoids human habitation and are considered to be restricted to protected areas.
Diet
The white-headed vulture is predominantly a carrion-eater; frequently flying lower than other vulture species, it is often the first species to turn up at a carcass. However, the species is probably also an active predator if the occasion arises. For example, incidences of pairs preying on species such as the mongoose, monitor lizard, tree squirrel and scrub hare have been recorded.
Breeding
White-headed Vulture’s nests are situated on the top of tall trees, such as the baobab or an acacia, emergent from surrounding woodland. Their nest is a large platform made with sticks, and sparsely lined with dried grasses. Little by little, this lining becomes covered by disintegrated pellets. Breeding season occurs from May to August. This species nests solitary. Female lays only one white egg, spotted with reddish-brown and lilac. Incubation lasts about 43-54 days, by both parents. The chick is fed by both parents, by regurgitation(mouth-to-mouth). It remains at the nest for about 115 days, where they are fed by adults. After fledging, parents feed them at nest for another six months.
Population
According to the IUCN Red List, they are classed as Critically Endangered(CR). An old estimate of 7,000-12,500 mature individuals was extrapolated from a number of regional estimates. This equates to 10,500-18,750 individuals in total. However, a new estimate of the global population suggests the population is much smaller, consisting of just 5,500 individuals. This equates to just 3,685 mature individuals here placed in the band 2,500-9,999 mature individuals. The species is thought to be declining at an extremely rapid rate.
Threats
Reductions in populations of medium-sized mammals and wild ungulates, as well as habitat conversion throughout its range best explain the current decline. Additional threats include indirect poisoning
at baits set to kill jackals in small-stock farming areas, and in East Africa at poisoned baits set for larger mammalian carnivores such as lions and hyenas, and, particularly in East Africa, secondary poisoning from carbofuran and other poisons. Deliberate poisoning to prevent vultures drawing attention to poaching activities has also been documented. Exploitation for the international trade in raptors also poses a threat. In 2005, 30 individuals of this species were confiscated by the Italian authorities. The species is recorded in trade in West and Central Africa. In South Africa, this species is captured for use in traditional medicines and in Zambia White-headed Vultures have apparently been intentionally killed for use in witchcraft. Breeding birds may readily desert nests in areas of high human disturbance. The species is highly sensitive to land-use and is highly concentrated in protected areas. Potential introduction of the non-steroidal anti-inflammatory drug diclofenac, which is fatal to Gyps spp. when ingested at livestock carcasses may represent a potential future threat to the species, although livestock have not been recorded as a potential food source for this species.
Conservation
Conservation and Research Actions Underway
CITES Appendix II. This species currently occurs throughout much of southern and East Africa's protected areas network. It is classified as Vulnerable in Namibia, Critically Endangered in Uganda and South Africa, Lesotho and Swaziland. Individuals were marked with patagial tags in Fouta Djallon vulture sanctuary, Guinea, in 2007 to monitor movements and for a toxicological assessment of the vulture population of the park. Additional studies to monitor the movement of individuals within and between protected areas is under way in South Africa. In 2007, a survey began to establish the extent of diclofenac use for veterinary purposes in Tanzania, and in 2008 an awareness-raising campaign at a conference of the World Organisation for Animal Health in Senegal led to a resolution being adopted unanimously by more than 160 delegates to request Members to consider their national situation with the aim to seek measures to find solutions to the problems caused by the administration of diclofenac in livestock. At the 2014 Conference of the Parties of the Convention on Migratory Species, a set of guidelines to address poisoning was formally adopted. The Hawk Conservancy along with the Endangered Wildlife Trust are currently working on providing training and equipment for anti-poisoning teams so that field staff will have the skills and equipment to respond to a neutralise poisoned carcasses. Ongoing monitoring occurs in South Africa, Botswana, Kenya and Tanzania.
Conservation and Research Actions Proposed
Carry out co-ordinated surveys throughout the range of this species to clarify its population size and trends. Continue to raise awareness about the impact of poisoning on this species, and attempt to reduce the human-wildlife conflict that motivated the poisoning of carrion. Enforce anti-poisoning legislation. Minimise disturbance at nests. Eliminate the veterinary use of diclofenac and other toxic drugs in Africa. Limit the use of lead based ammunition. Carry out education and awareness programmes, particularly targeted at farmers, to reduce persecution, unintentional poisoning and hunting for cultural reasons, and continue to carry out the deployment of anti-poisoning training and equipment. Promote measures to join up isolated protected areas and where suitable consider translocating birds to expand the range of the species, and research the movement ecology of this species to determine the extent of movement between breeding populations. A number of recommendations were produced at the 2012 Pan-Africa Vulture Summit: 1) Regulate import, manufacture and sale of poisons; 2) Legislate and enforce measures to prosecute those involved in illegal killing and trade in vulture species; 3) Protect and effectively manage breeding sites; 4) Ensure new energy infrastructure is vulture-friendly and modify existing unsafe infrastructure; 5) Support activities to conserve vulture populations, including research and outreach activities.