Red-headed Vulture (Sarcogyps calvus)

[order] ACCIPITRIFORMES | [family] Accipitridae | [latin] Sarcogyps calvus | [authority] Scopoli, 1786 | [UK] Red-headed Vulture | [FR] Vautour royal | [DE] Kahlkopf-Geier | [ES] Buitre Cabecirrojo | [NL] Indische Oorgier

Subspecies

Genus

Physical charateristics

The bare skin on the head varies from red to orange. The ruff is black, and there is a circle of white down across the breast. Th rest of the plumage is black, browner around the area of the crop and lower back and rump; two white patches just above the thigh joint, and a white line at the base of the flight quills visible when the wing is extended. The iris can be reddish brown, yellow or red. The cere, feet and legs are also red. The weight of this bird is generally between 3.7Kg and 5.4Kg, and the wingspan is around 2 Meter. In immature plumage, the bird is pale brown above and below; with dark brown to black wing and tail quills. The head is covered with white down, and some white below on the throat. The iris is clearly brown; the cere, feet, and bare skin reddish, paler than in the adult.

Range

Oriental Region : widespread. Sarcogyps calvus occurs in Pakistan (previously regular, now a rare straggler with two in Tharparker in 2002 the first record since 1980), Nepal (uncommon), India (sparsely distributed and declining, now rare or absent from some areas, e.g. parts of Gujarat and the north-eastern states, but still fairly common in the west Himalayan foothills), Bangladesh (rare in the north-west), Bhutan, Myanmar (rare resident; recent records come mainly from Mount Victoria, with up to 11 in Shan state in 2003 the first recent documented records in the east of the country), China (unrecorded in Yunnan since the late 1960s; possibly occurs in south-east Tibet), Thailand (near extinct in the country), Laos (previously widespread and common, but now extremely rare and restricted to the south), Vietnam (previously regular in central regions, now extremely rare), Cambodia (previously common, now rare and restricted to the northern and eastern plains), peninsular Malaysia (previously locally common in north, now absent), Singapore (formerly occurred, apparently now absent).

Habitat

It frequents open country (often near human habitation), well-wooded hills and dry deciduous forest with rivers, usually below 2,500 m. Nesting has been recorded in tall trees. It occurs at lower density than Gyps vultures owing to its predominantly territorial behaviour, and movements are poorly known. Vultures play a key role in the wider landscape as providers of ecosystem services, and were previously heavily relied upon to help dispose of animal and human remains in India. This is mostly a solitary vulture, seldom seen in numbers, although it may be relatively common. Along the coast of Thailand and Indo-China it is the commonest of the vultures. It frequents uninhabited jungle and cultivated areas alike and of all vultures is most likely to be found in forest or dense woodland with high rainfall. It roosts on trees, occasionally on buildings or cliffs, often in some numbers together. It has similar habits to other big vultures, that is, it gets on the wing as soon as the day warms up and the thermal currents are adequate. Thereafter it spends much of the day soaring, but it is quick to locate a carcase and descend to it. Having found one, many of these vultures commonly stay in the general area, and roost on any available big tree near it. At such times ten or more may collect together.

Reproduction

It performs spectacular aerial displays, the pair soaring together at a height, diving and twisting over and round one another. Mating normally takes place on a tree branch near the nest, and is accompanied, as is display, by loud roaring calls. Nests are built in trees, at any height from three to a hundred feet above the ground. They are usually situated in cultivated or inhabited areas, but sometimes in uninhabited jungle. Low bushes or Euphorbias will be used if large trees are not available. They do not nest in colonies of their own kind, but may build in the same tree as other vultures, such as White-backed Vultures. The nests are comparatively small and slight when first constructed, but are used year after year and become larger with time, up to five feet across and four feet deep. They are made of sticks, and leafy branches with the leaves on, with oddments such as pieces of skin or hair in the nest cup, which is often filthy. Both birds build the nest; the male is said to bring materials which the female incorporates in the nest. One egg is laid, a broad oval, fine in texture and smoother than other vultures’ eggs, sometimes slightly glossy, plain greenish white, or pure white. Both sexes incubate, the female through the night and in the early mornings and evenings, the male through the day. Greeting ceremonies take place at change-over, accompanied by loud roaring calls. The incubation period is about 45 days.

Feeding habits

Carrion, including small dead animals neglected by other vultures. Its habits at a carcase are like those of other large vultures, but it is not really able to dominate either the Indian Griffon Vulture (Gyps indicus) or Indian White-backed Vulture (Gyps bengalensis), and often gives way to them. It is much more likely than either of these species to come to the carcase of a small animal, and will descend to small creatures killed by a grass fire, or rats trapped and left lying in paddy fields, much like the Trigonoceps of Africa. In flight it appears as a more graceful flier than the White-backed Vulture, the wings being held slightly above the body. It is attracted to grass fires and will soar about them for long periods, occasionally descending to the ground to pick up a titbit.

Video Red-headed Vulture

httpv://www.youtube.com/watch?v=H-8V4EL0ZCo

copyright: J. del Hoyo

Conservation

This species has suffered an extremely rapid population reduction in the recent past which is likely to continue into the near future, probably largely as a result of feeding on carcasses of animals treated with the veterinary drug diclofenac, perhaps in combination with other causes. For this reason it is classified as Critically Endangered.
The disappearance of vultures from Asia is linked to a suite of factors: notably the demise of wild ungulates, the intensification of agriculture, increased sophistication of waste disposal techniques, direct persecution and disease. However, rapid declines over the last eight years are believed to have been driven by the pharmaceutical NSAID diclofenac used to treat livestock, which has proven highly toxic to vultures, causing mortality from renal failure resulting in visceral gout. It seems plausible that this species previously had less exposure to the toxin owing to competitive exclusion from carcasses by Gyps spp. vultures.

Migration

It is resident and non-migratory throughout its range, but no doubt wanders according to food supplies.

Distribution map