Petroica nera

Identificazione

The black robin is a small, sparrow-sized bird measuring 10–15 centimetres (3.9–5.9 in). Its plumage is almost entirely brownish-black, with a black bill and brownish-black yellow-soled feet.<p>Females are usually slightly smaller than males. Male songs are a simple phrase of 5 to 7 notes. Its call is a high-pitched single note. Their eyes are dark brown. Black robins moult between December and March.

Tassonomia

Nome scientifico

Petroica traversi

Autorità

(Buller, 1872)

Ordine

Passeriformi

Famiglia

Petroicidae

Genere

Petroica

Areale e habitat

Black robins live in low-altitude scrub forest remnants. They are entirely insectivorous, feeding on the forest floor or on low branches, and preferring to nest in hollow trees and tree stumps. To shelter from the strong winds and rough seas around the islands, they frequent the lower branches of the forest, or in flat areas with deep litter layers. They prefer woody vegetation under the canopies of trees such as akeake.

Migrazione

Resident species

Comportamento

Black robins are territorial. Males will patrol and defend their areas. Females have been known to chase away other females. They make short flights from branch to branch and do not fly long distances.<p>Black robins forage in the leaf litter on the ground for grubs, cockroaches, wētā, and worms. Black robins will hunt for food during the day and night and have good night vision.<p>Black robins will generally start to breed at two years of age. The female robin will make the nest, and while she lays and incubates the eggs, the male will feed the female for a rest.<p>Eggs are laid between early October and late December. A second clutch may be laid if the first is unsuccessful. The clutch size varies from one to three eggs, but two is typical. Eggs are creamy in colour with purple splotches. When the eggs are laid, the female will sit on them to keep them warm until they hatch, after about 18 days. Then both parents will help to feed the chicks. Young robins stay in the nest for about 23 days after hatching, but even after leaving the nest the parents will continue to feed them until they are about 65 days old. This period of parental care is longer than would normally be expected for a bird of this size. After leaving the nest, chicks often spend the first day or two on the ground learning to use their wings, and here they are exposed to predators.<p>Survivorship between 1980 and 1991 indicates a mean life expectancy of four years. "Old Blue", the sole breeding female in 1980, lived for over 14 years. Some black robins can live from 6 to 13 years.

Conservazione

Tendenza della popolazione

stable