Palm-nut Vulture

识别特征

This is a nearly unmistakable bird as an adult. At 1.3–1.7 kg (2.9–3.7 lb) in weight, 60 cm (2.0 ft) in length and with a wingspan of 1.50 m (4.9 ft), this is the smallest Old World vulture. Its plumage is all white except for black areas in its wings and tail. It has a red patch around each eye. The juvenile, which takes 3–4 years to mature, is brown with yellow eye-patches. In flight, this species resembles an eagle more than a typical vulture, and it can sustain flapping flight, so it does not depend on thermals. With its extensive white plumage, and black wing- and tail-feathers, the adult palm-nut vulture can be crudely mistaken for both the African fish-eagle and the Egyptian vulture, but clearly lacks the chestnut body of the former and the white tail of the latter.[failed verification]<p>The sexes are identical in appearance, with the female being the same size as the male. Juveniles on the other hand are predominately brown with partially black wings and take a lengthy three to four years to make the transition into the adult plumage.

分类信息

The palm-nut vulture was formally described in 1788 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with the eagles, hawks and falcons in the genus Falco and coined the binomial name Falco angolensis. Gmelin based his description on the "Angola vulture" that had been described in 1781 by the English ornithologist John Latham in his multi-volume work A General Synopsis of Birds. The Leverian Collection in London included two specimens that had been collected in Angola. The palm-nut vulture is now placed in the genus Gypohierax that was introduced for the species in 1836 by the German naturalist Eduard Rüppell. The genus name combines the Ancient Greek gups meaning "vulture" with hierax meaning "hawk". The species is monotypic: no subspecies are recognised.

学名

Gypohierax angolensis

命名信息

(Gmelin, JF, 1788)

目

Accipitriformes

科

Accipitridae

属

Gypohierax

分布与栖息地

Palm-nut vultures are found throughout most of the coastal areas of the African continent from The Gambia to Kenya and as far South as South Africa. The total African population is estimated to be 80,000 pairs. There are approximately 40 birds in South Africa.<p>The only Southern African subregions to have resident breeding pairs of palm-nut vultures are South Africa and Mozambique. The breeding distribution of the palm-nut vulture during the 1970s census period was centred on the Raffia palm groves of the Kosi Bay system and Mtunzini. Its distribution is linked to the presence of the Raffia palm Raphia australis at all permanently occupied sites, and the existence of this species at Mtunzini is entirely due to the artificial cultivation of Raffia palms. Currently there are 7 known nesting sites in South Africa and a total of 40 individual birds.<p>As the name suggests, the distribution of the palm-nut vulture closely tracks that of oil (Elaeis guineensis) or raffia (Raphia sp.) palms. Consequently, it is most common in coastal forests and mangrove swamps below 1,500 m (4,900 ft), but also occurs in wet savannas.

迁徙

Resident species

行为

Migration pattern: Resident species.

保护状况

Population trend: stable.

种群趋势

stable