Eurilaimo di Hose

Identificazione

Hose's broadbill is 19–21 cm (7.5–8.3 in) long, with females weighing 92 g (3.2 oz) on average and males weighing 102–115 g (3.6–4.1 oz). Males have bright shimmery green upperparts, with a large tuft of feathers on the forehead covering most of the bill and a thin pale green eye-ring. There is a black spot in front of the eyes and black patches behind the ear-coverts, on the back of the neck, and across the upper back. The wing coverts have conspicuous circular black spots and the flight feathers are black with green edges. The breast is indigo blue and the belly and undertail coverts are azure blue.<p>Females differ in their smaller forehead tufts, paler upperparts with a slight olive tint, and lime-green underparts with sky blue instead of azure blue. They also have lime green eye-rings and no black on the head other than the spot in front of the eye. The iris is blackish, the bill is dark brownish-black to black, and the feet are dark olive green. Juveniles are mostly like females, but juvenile males have dark feathers on the back of the neck. Immature males are similar to adult males, but lack most of the head markings and have less blue on the underparts.<p>The species can be differentiated from the other two species of Calyptomena , which also occur in Borneo, by its blue underparts. It can be told apart from the green broadbill by its larger size and spots on the wings, instead of bars as in the latter. Whitehead's broadbill is larger and has a black patch on the breast.

Tassonomia

Hose's broadbill was described as Calyptomena hosii by the British naturalist Richard Bowdler Sharpe in 1892 based on specimens collected from Mount Dulit, Borneo. The name of the genus, Calyptomena, is from the Ancient Greek words kaluptos, meaning covered, and mēnē, meaning moon. The specific name hosii, as well as the common name, is in honour of the British zoologist Charles Hose, who collected the holotype of the species. Hose's broadbill is the official common name designated by the International Ornithologists' Union. Other names for the species include blue-bellied broadbill, Hose's green broadbill, magnificent broadbill, and magnificent green broadbill.<p>Whitehead's broadbill is one of three species in the genus Calyptomena, a genus of three bright green broadbills found in Southeast Asia. Calyptomena is one of two genera in the family Calyptomenidae, the other being Smithornis, a genus of three rather dull-coloured species found in Africa. Although species-level relationships within the family are unclear, both the genera are monophyletic (including all descendants of a common ancestor) taxa that are sister (most closely related) to each other.

Nome scientifico

Calyptomena hosii

Autorità

Sharpe, 1892

Ordine

Passeriformi

Famiglia

Calyptomenidae

Genere

Calyptomena

Areale e habitat

Endemic to the island of Borneo, Hose's broadbill inhabits the northern and central parts of the island, where it is found discontinuously from Mount Kinabalu to the Müller Mountains, Kayan Mentarang, the Dulit Range, the Sambaliung Mountains, and the Sangkulirang Peninsula. It is also found in southeastern Borneo. It may be locally migratory depending on the fruiting seasons of trees it feeds on.<p>Hose's broadbill is mainly found on hill slopes, inhabiting dipterocarp forest, lower montane forest, lowland forest on hills, and forests with limestone pinnacles (rock columns). It is mainly found at elevations of 600–1,220 m (1,970–4,000 ft), but can be seen as low as 300 m (980 ft) and as high as around 1,680 m (5,510 ft).

Migrazione

Resident species

Comportamento

The generation length (average age of parents in the current population) of the species is 4.2 years.<p>The species is omnivorous but mainly feeds on fruit, such as figs and berries. It has been recorded eating soft, greyish-yellow berries and small orange figs covered with short, spiky hairs. It also eats insects and leaf buds. It generally forages in the lower levels of the forest. Hose's broadbills are mainly seen alone or in pairs, but small flocks of 6–8 birds are found at fruiting trees.<p>Breeding has been observed from April to October. It makes a delicate hanging nest out of dead leaves, rattans, and bamboo, with an outer covering of green moss and lichen and a trailing "tail" made of rattan leaves. One nest measured around 25 cm × 15 cm (9.8 in × 5.9 in) and was hanging from a low, sagging branch 1.5 m (4.9 ft) high. Clutches have 2–4 eggs. The time taken for incubation and fledging is unknown.

Conservazione

Tendenza della popolazione

declining