Casuario settentrionale

Identificazione

The northern cassowary has a hard and stiff black plumage, blue facial skin and a casque on top of the head. It has a bright red or yellow coloured neck and wattle. The feet are huge and strong with long, dagger-like claw on its inner toe. The sexes are similar in appearance. The male, at 30 to 37 kg (66 to 82 lb), is smaller than the female, at an average of 58 kg (128 lb), making it the fourth heaviest living bird species after the common ostrich, Somali ostrich and the southern cassowary. These birds measure .mw-parser-output .frac{white-space:nowrap}.mw-parser-output .frac .num,.mw-parser-output .frac .den{font-size:80%;line-height:0;vertical-align:super}.mw-parser-output .frac .den{vertical-align:sub}.mw-parser-output .sr-only{border:0;clip:rect(0,0,0,0);clip-path:polygon(0px 0px,0px 0px,0px 0px);height:1px;margin:-1px;overflow:hidden;padding:0;position:absolute;width:1px}149 cm (4 ft 10+1⁄2 in) long and stand 1.5–1.8 m (4 ft 11 in – 5 ft 11 in) in height. Compared to the southern cassowary, the northern cassowary has a slightly shorter bill, at 12 to 13.7 cm (4.7 to 5.4 in), but a slightly longer tarsal length, at 28 to 33.2 cm (11.0 to 13.1 in).

Tassonomia

Edward Blyth first identified the northern cassowary from a specimen from an aviary located in Calcutta, India, in 1860. It is the most recently discovered of all the cassowary species. The genus name Casuarius is derived from the Malay word kesuari "cassowary", while the species name unappendiculatus refers to the species' single wattle. Officially, there are no subspecies, though some authors list several subspecies.

Nome scientifico

Casuarius unappendiculatus

Autorità

Blyth, 1860

Ordine

Casuariiformes

Famiglia

Casuariidae

Genere

Casuarius

Areale e habitat

The northern cassowary is distributed and endemic to coastal swamp and lowland rainforests of northern New Guinea and the islands of Yapen, Batanta and Salawati. They prefer elevations below 490 m (1,610 ft).

Migrazione

Resident species

Comportamento

As with other cassowaries, the northern cassowary is a shy and solitary bird. Their diet consists mainly of berries, fruits and small animals, such as mice, rats, frogs, snakes, lizards, smaller birds and a variety of small insects and snails. They will eat dead animals when they find them. The young have been observed to eat the feces of the males raising them and clutch mates. Adults will eat their own feces as it often contains undigested fruits. They make grunting and hissing sounds, like other cassowaries.<p>In the breeding season, the polygamous female lays three to five green eggs on a well camouflaged nest prepared by the male; she then leaves the nest and eggs to find another mate. The male incubates the eggs and raises the chicks alone for about nine months.

Conservazione

Although subject to ongoing habitat loss and overhunting in some areas, as of 2017, the northern cassowary is evaluated as Least concern on the IUCN Red List of Threatened Species, as population size estimates suggest that populations are actually larger than previously estimated. However, it is the most threatened of the three extant cassowary types as of 2022. Hunting is still considered the biggest threat. Native people use the bones and eggs, and take the chicks to be raised for meat. As logging opens up more areas of the forest, hunting will be more of a problem. Their occurrence range is 186,000 km2 (72,000 sq mi) and a 2000 estimate placed their numbers at 9300.

Tendenza della popolazione

declining