Difference between revisions of "Red-headed vulture"
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Latest revision as of 13:23, 22 June 2019
|Population||<10,000 (2016 est.)|
|Conservation status||Critically endangered|
The red-headed vulture (Sarcogyps calvus) is a species of Old World vulture, and found in large parts of southern and Southeast Asia, and currently endangered as a result of ingestion of livestock meat containing diclofenac.
Red-headed vultures have a length of 30 to 34 inches, a wing span of 6.5–8.5 feet, and a body weight 7.7–13.9 pounds. The long, relatively narrow wings are widest at the base and towards the end quite clearly pointed. The tail is short and slightly wedge-shaped. Females are slightly larger than males.
This vulture is predominantly black in color, with lower back and the base of the wings a lighter, more brownish color. Contrasting to the dark remaining plumage are the white breast at the base of the throat and upper legs. Head and neck are largely yellowish red or orange red, with large, equally colored skin lobes on the either side of the neck. When excited, these skin lobes become a more radiant red. The slightly pronounced, fluffy neck cape is black on the neck sides and neck.
Juveniles are somewhat lighter in color, medium-brown above, with a light brown to white underside. The head and neck are paler in color, with no skin lobes. Adult plumage is not worn until after five years.
Range and habitat
The original distribution area covered large parts of South and Southeast Asia, stretching from the southern edge of the Himalayas in Pakistan, India, Nepal and Bhutan, and southward over most of the Indian subcontinent. In addition, the area of the species encompassed nearly all of Indo-China from the north of Myanmar and south-west China to the southern tip of Vietnam, and with its scattered deposits extended to the south of the Malay Peninsula.
In the last decades, the distribution area of the red-headed vulture has greatly diminished. The species is present today in almost the entire southern half of the Indian subcontinent as well as in the west. In Indo-China, their numbers are small and very fragmented.
The species inhabits a wide range of semi-open and open habitats from dry forests and dense tree-tops to semi-deserts, river valleys, coasts and agricultural areas. Red-headed vultures live from sea level to 7,600 feet in elevation.
The red-headed vulture is often sitting freely on a tree top, more rarely on rocks or buildings. They search for food in a circular pattern, either looking at the ground or by following other vultures; they have also been known to take advantage of brushfires, landing on game freshly killed by the flames.
Red-headed vultures live as individual pairs. The courtship consists of common circles and "tandem flights" in which one partner copies each flight of the other bird, as well as some spectacular dive flights, twists in the air, and mutual gripping of the catches.
The nests are often built in agricultural areas or other open landscapes and mostly in large, tall trees, occasionally also in the forest and in semi-desert, in the absence of other possibilities even on a bush at a height of 10 feet.
Newly built nests are often rather small, consisting of sticks and branches and are lined with straw, remains of carrion and garbage. The nesting period is from February to March, with a single egg laid. The incubation takes about 45 days, but to date the rearing and fledging of the chick is so far not known.
The red-headed vulture has gone through a severe decline in numbers since the 1990s, the population decreasing by 94% between 2000 and 2003 in India alone. The blame fell on the ingestion of carrion meat containing diclofenac, a non-steroidal anti-inflammatory drug (NSAID) meant as an anti-biotic for livestock; the drug causes kidney and renal failure in vultures and is fatal to the birds. Diclofenac is routinely used throughout southern Asia, and in largely-Hindu India its use proved to be particularly problematic where Hindus are forbidden to consume beef. In these regions dead cattle are usually left at the place where they have died, where they are eaten by the vultures.
Diclofenac was banned very quickly in both Nepal and India after recognizing its harmful effect on vultures. This contributed significantly to the fact that with the decline of vultures the population of rats and the number of carrion-consuming feral dogs greatly increased; with both came an increase in the number of rabies cases in humans. Despite the ban, diclofenac is still used in parts of southern Asia.
Several breeding programs have been started, including a rearing station in Haryana, in an effort to repopulate this and other species of vultures. As a further protective measure, untreated carcasses are laid out in selected places in order to bind the vultures, which are very loyal to the location, to these places until diclofenac has largely disappeared from the food cycle.