Avvoltoio cappuccio

Identificazione

The hooded vulture is a typical vulture, with a head that is usually pinkish-white, but flushes red when agitated, and a grey to black "hood". It has fairly uniform dark brown body plumage. It has broad wings for soaring and short tail feathers. This is one of the smaller Old World vultures. They are 62–72 cm (24–28 in) long, have a wingspan of 155–180 cm (61–71 in) and a body weight of 1.5–2.6 kg (3.3–5.7 lb). Both sexes are alike in appearance, although females often have longer eyelashes than males. Juveniles look like adults, only darker and plainer, and body feathers have a purplish sheen. <p>Usually silent, but gives a shrill, sibilant whistle during copulation, and thin squealing calls both at nests and carcasses.<p>It breeds in a stick nest in trees (often palms) in much of Africa south of the Sahara, laying one egg. Birds may form loose colonies. The population is mostly resident and sedentary, rarely moving more than 200 km.

Tassonomia

Nome scientifico

Necrosyrtes monachus

Autorità

(Temminck, 1823)

Ordine

Accipitriformi

Famiglia

Accipitridae

Genere

Necrosyrtes

Areale e habitat

Although hooded vultures have relatively small home ranges, they are widely distributed across Africa. It occurs in Senegal, Mauritania, Guinea-Bissau, The Gambia, Niger and Nigeria in West Africa; in East Africa it is found in Chad, Sudan, South Sudan, Ethiopia and Somalia; in southern Africa it has been recorded in northern Namibia, Botswana, Zimbabwe, Mozambique and South Africa.<p>Within South Africa, the species is essentially restricted to the Kruger National Park and surrounding protected areas in Mpumalanga and Limpopo provinces, though vagrants have been recorded further west in Kwa-Zulu Natal and Kgalagadi Transfrontier Park.

Migrazione

Resident species

Comportamento

Like other vultures hooded vultures are scavengers, feeding mostly from carcasses of dead animals and waste which they find by soaring over savanna and around human habitation, including waste tips and abattoirs. They do however also feed on insects, and conglomerate in large numbers during insect emergences, for example termite emergences where they associate with Steppe Eagles. They are non-specialised, highly versatile scavengers and are commensal with humans in West Africa. They often move in flocks (50-250 individuals) in West Africa, especially when foraging at abattoirs or elephant carcasses, while in southern Africa they are solitary and secretive, making them hard to spot when nesting. They are known to follow scavenging African wild dogs and hyaenas. <p>This vulture is typically unafraid of humans, and frequently gathers around habitation. It is sometimes referred to as the “garbage collector” by locals.[citation needed] In Ghanaian universities, a significantly higher number of hooded vultures exist in the residential parts of the campus relative to the non-residential parts, and densities are correlated with the academic calendar, with numbers of individuals increasing during school terms. 45% of students at these campuses are defecated on by hooded vultures at least once a month, according to interviews.<p>Southern African hooded vulture populations have smaller home ranges than most other Old World vulture species for which data exists, though less is known about home ranges of East and West African populations. They are most active during the day, and their ranges are smaller in the dry breeding season, when their movement is constrained by a nest site location to which they must return regularly to incubate their eggs and provision their fledglings. In both the northern and southern hemisphere populations, breeding takes place in the dry summer season.<p>They prefer to build nests in well-foliaged trees along watercourses, with the nest placed a prominent fork within the tree canopy at an average height of over 15m. They have however also been observed in a variety of biomes, some where tall trees are rare. They have been recorded in open grasslands, deserts, wooded savanna, forest edges and along coasts. They tend to occur in higher densities where populations of larger Gyps vultures are low or nonexistent. It occurs up to 4,000 m, but is most numerous below 1,800 m.<p>Hooded vultures lay a clutch of one egg, and the incubation period lasts 46-54 days, followed by a fledging period of 80-130 days. Young are dependent on their parents for a further 3-4 months after fledging. Measurements of nesting success at the Olifants River Private Nature Reserve, South Africa showed success of 0.44-0.89 offspring per pair per year in 2013 and 0.50-0.67 offspring per pair per year in 2014.

Conservazione

Tendenza della popolazione

declining