White-headed Vulture

The white-headed vulture is a medium-sized vulture, 72–85 centimetres (28–33 in) in length and with a wingspan of 207–230 centimetres (81–91 in). Females have an average weight of 4.7 kilograms (10 lb), while males are generally lighter at 4 kilograms (8.8 lb) 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. The white-headed vulture is the only vulture species with a sexually dimorphic plumage. Males have dark grey secondary feathers, while in females the secondaries are white.

The white-headed vulture is widely spread throughout sub-Saharan Africa, occurring from Senegal and Gambia east to Somalia and south to South Africa and Eswatini. It is locally uncommon to common. A total population of 10,500–18,750 individuals has been estimated, but newer estimates following recent declines suggest a population of just 5,500 individuals. It is estimated that 400 protected areas contain 1893 white-headed vulture nests, with 721 nests occurring in East Africa, 548 in Central Africa, 468 in Southern Africa and 156 in West Africa. The species prefers mixed, dry woodland at low altitudes. It occurs at elevations of up to 4,000 m (13,000 ft) in Ethiopia, perhaps 3,000 m (9,800 ft) in Kenya, and can be found in thorny Acacia-dominated landscape in Botswana. It generally avoids human habitation, and is largely restricted to protected areas. For example, the Kruger National Park and neighbouring conservation areas hold the largest population of the species in South Africa.

The species is long-lived and appears to be loyal to a territory where it remains resident. It builds nests in trees (mostly acacias or baobabs). Senegalia species are also preferred, with nests occurring on the top of the canopy in low relief, flatter areas. These vultures usually lay a single egg a couple of months after the rainy season has ended and the dry season is underway. It is generally a solitary species and nests in isolated, possibly territorial pairs. From a study across 73 pairs, the average productivity of 55 breeding attempts was 0.69 chicks per pair. White headed vultures are known to exhibit a characteristic breeding behaviour. From a study in the Kruger National Park, copulation only occurred on the nest and is described as a subtle and inconspicuous process that lasts approximately 15 to 20 seconds. Preceding actual copulation the female bird stands perpendicular to and in front of the male. The "head turning" behaviour, typically observed in other aegypiine vultures, was not observed. The sound made by the birds during copulation is unusual and best described as a very deep squeak, but longer than a grunt.