Difference between revisions of "Griffon vulture"
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Latest revision as of 13:17, 22 June 2019
|Population||648,000-688,000 (2015 est.)|
|Conservation status||Least concern|
The griffon vulture or Eurasian griffon (Gyps fulvus) is a large representative of the subfamily of Old World vultures (Aegypiinae), and found in parts of Europe and much of central Asia.
The griffon vulture is a large bird, with a body length of 37–48 inches, a wingspan of 7.5–9.2 feet, and they weigh 14 to 25 pounds. Females are slightly larger than males, but the differences are slight.
The body, leg feathering, and small and middle lower and upper wings are pale brown to light reddish brown in adult birds, with light-colored strokes especially on the underside. Primary and secondary flight feathers are almost monochrome black-gray. Head and neck are covered in a short, whitish down. The loose, dense fluffy neck cape is white. The strong beak is yellowish to greenish-yellow and at the base pale gray. The unfeathered parts of the legs and the toes are gray.
- Gyps fulvus fulvus; Northwestern Africa, Iberian Peninsula to Middle East
- Gyps fulvus fulvescens; Central Asia: Afghanistan, Pakistan and northern India to Assam
The subspecies G. f. fulvescens has been considered by some authorities to be more closely related to the Himalayan griffon vulture (Gyps himalayensis), based on molecular genetic examination, in addition to the paler, more reddish plumage than that of the nominate subspecies G. f. fulvus. According to this study, fulvescens' relatives, and hence the sister taxis, is Rüppell's vulture (Gyps rueppelli), which is found in Central Africa.
Griffon vultures prefer mainly open and dry landscapes, including steppes, semi-desert, mountain slopes and plateaus, but also will use cleared agricultural areas. The species occurs at elevations of 0 to 1,500 feet, and have been seen at elevations over 11,000 feet. For resting or breeding they use vertical or steep rock cliffs, usually with an overhang.
The food consists exclusively of fresh or decaying carcasses; the internal organs, stomach content, and muscle meat of medium to large mammals are eaten. The strong bill is capable of tearing open the abdominal cavity, which is usually first in order to reach the internal organs with the long neck. Often, however, natural body openings are also expanded, in particular the anal opening. A mass of vultures will strip the carcass clean within a short time, and they occasionally eat so much that they have to vomit out some of the meat in order to be able to leave.
Griffon vultures are very sociable and usually breed in colonies, which can include more than 100 breeding pairs. The couples defend against the opposite species only the immediate nest area. The courtship consists of common circles and "tandem flights" in which one partner copies each flight of the other bird. Occasionally the male takes some nesting material into the beak and then follows the female in the air for a few minutes.
The nests are built on ledges of rock walls, under rock overhangs or in open niches and caves. They consist of sticks and twigs and are laid out with green branches or grass. The breeding period is from the end of December to the end of March. A single egg is laid, which is usually pure white with small red-brown spots. Both partners take turns incubating, which takes 47 to 57 days. The chick is alternately supplied with food by both partners, which is brought to the nest in the goitre and regurgitated there. The young bird leaves the nest on average after about 135 days, in southern Europe about mid-July to mid-August.
- Jeff A. Johnson, Heather R. L. Lerner, Pamela C. Rasmussen, and David P. Mindell: Systematics within Gyps vultures. A clade at risk; BMC Evolutionary Biology, Vol. 6 (2006)