Faraona dal casco

Identificazione

The helmeted guineafowl is a large, 53 to 58 cm (21 to 23 in) bird with a round body and small head. They weigh about 1.3 kg (2.9 lb). The body plumage is gray-black speckled with white. Like other guineafowl, this species has an unfeathered head, which in this species is decorated with a dull yellow or reddish bony knob, and bare skin with red, blue, or black hues. The wings are short and rounded, and the tail is likewise short. Various subspecies are proposed, differences in appearance being mostly a large variation in shape, size, and colour of the casque and facial wattles.

Tassonomia

The helmeted guineafowl was formally described by Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae under the binomial name Phasianus meleagris. In 1764, Linnaeus moved the helmeted guineafowl to the new genus Numida. The genus name Numida is Latin for "North African".<p>In the early days of the European colonisation of North America, the native wild turkey (Meleagris gallopavo) was confused with this species. The word meleagris, Greek for guineafowl, is also shared in the scientific names of the two species, though for the guineafowl it is the species name, whereas for the turkey, it is the name of the genus and (in inflected form) the family.<p>The nine recognised subspecies are:

Nome scientifico

Numida meleagris

Autorità

(Linnaeus, 1758)

Ordine

Galliformi

Famiglia

Numididae

Genere

Numida

Areale e habitat

They breed in warm, fairly dry and open habitats with scattered shrubs and trees such as savanna or farmland.

Migrazione

Resident species

Comportamento

This is a gregarious species, forming flocks outside the breeding season typically of about 25 birds that also roost communally. Guineafowl are particularly well-suited to consuming massive quantities of ticks, which might otherwise spread Lyme disease. These birds are terrestrial, and prone to run rather than fly when alarmed. Like most gallinaceous birds, they have a short-lived, explosive flight and rely on gliding to cover extended distances. Helmeted guineafowl can walk 10 km and more in a day. Their bodies are well-suited for running and they are remarkably successful in maintaining dynamic stability over rough terrain at speed. They make loud harsh calls when disturbed.<p>Their diet consists of a variety of animal and plant foods. During the nonbreeding season, N. meleagris consumes corns, tubers, and seeds, particularly of agricultural weeds, as well as various agricultural crop spillage. During the breeding season, more than 80% of their diet may be invertebrates, particularly arthropods such as beetles. Guineafowl are equipped with strong claws and scratch in loose soil for food much like domestic chickens, although they seldom uproot growing plants in so doing. As with all of the Numididae, they have no spurs. They may live for up to 12 years in the wild.<p>Males often show aggression towards each other, and partake in aggressive fighting, which may leave other males bloodied and otherwise injured. They attempt to make themselves look more fearsome by raising their wings upwards from their sides and bristling their feathers across the length of their bodies, and they may also rush towards their opponent with a gaping beak. The nest is a well-hidden, generally unlined scrape, and a clutch is normally some 6 to 12 eggs, which the female incubates for 26 to 28 days. Nests containing larger numbers of eggs are generally believed to be the result of more than one hen using the nest; eggs are large, and an incubating bird could not realistically cover significantly more than a normal clutch.<p>Domesticated birds, at least, are notable for producing very thick-shelled eggs that are reduced to fragments as the young birds (known as keets among bird breeders) hatch, rather than leaving two large sections and small chips where the keet has removed the end of the egg. Domesticated guinea hens are not the best of mothers, and often abandon their nests. The keets are cryptically coloured, and rapid wing growth enables them to flutter onto low branches barely a week after hatching.

Conservazione

Tendenza della popolazione

stable