Gyps rueppellii

Rüppell's vulture or Rüppell's griffon vulture (Gyps rueppelli) is a large vulture that can be found throughout the Sahel region of central Africa. The current population of 30,000 is decreasing due to loss of habitat, incidental poisoning, and other factors. Known also as Rüppell's griffon, Rueppell's griffon, Rüppell's griffin vulture, Rueppell's vulture and other variants, it is not to be confused with a different species, the griffon vulture (Gyps fulvus). Rüppell's vulture is named in honor of Eduard Rüppell, a 19th-century German explorer, collector, and zoologist. Rüppell's vulture is considered to be the highest-flying bird, with confirmed evidence of a flight at an altitude of 11,300 m (37,000 ft) above sea level. Their range extends through the Sahel region of Africa where they can be found in grasslands, mountains, and woodlands. Once considered common in these habitats, the Rüppell's vultures are experiencing steep declines, especially in the Western portion of their range. They are relatively slow birds, cruising at 35 kilometres per hour (22 mph), but fly for 6–7 hours every day and will fly as far as 150 kilometres (93 mi) from a nest site to find food. These are large vultures, noticeably outsizing the closely related white-backed vulture, with which they often occur in the wild. Adults are 85 to 103 cm (33 to 41 in) long, with a wingspan of 2.26 to 2.6 metres (7.4 to 8.5 ft), and a weight that ranges from 6.4 to 9 kg (14 to 20 lb). Both genders look alike: mottled brown or black overall with a whitish-brown underbelly and thin, dirty-white fluff covering the head and neck. The base of the neck has a white collar, the eye is yellow or amber, the crop patch deep brown. The head does not have feathers. This is an adaptation that occurred because of the Rüppell vulture's tendency to stick its head inside of its prey when eating. Without the adaptation, feeding would become extremely messy. Silent as a rule, they become vocal at their nest and when at a carcass, squealing a great deal. Rüppell's vultures commonly fly at altitudes as high as 6,000 metres (20,000 ft). The birds have a specialized variant of the hemoglobin alphaD subunit; this protein has a great affinity for oxygen, which allows the species to absorb oxygen efficiently despite the low partial pressure in the upper troposphere. A Rüppell's vulture was confirmed to have been ingested by a jet engine of an airplane flying over Abidjan, Ivory Coast on November 29, 1973 at an altitude of 11,300 m (37,000 ft). During August 2010 a Rüppell's vulture escaped a bird of prey site in Scotland, prompting warnings to pilots in the area to watch carefully due to the danger of collision.