Gray-throated Leaftosser

Identificazione

The grey-throated leaftosser is one of the larger members of genus Sclerurus. It is 16 to 18 cm (6.3 to 7.1 in) long and weighs 34 to 46 g (1.2 to 1.6 oz). The sexes are alike. The nominate subspecies has a grayish brown face with a somewhat scaly appearance. Its crown and back are rich chestnut-brown and its rump and uppertail coverts are a brighter reddish chestnut. Its flight feathers are rich brown and its tail is dark gray-brown. Its throat is grayish white with a darker lower edge, its breast dark rufous with some pale streaks, its belly dark brown, and its flanks and undertail coverts a richer brown. Its iris is dark brown to brown, its maxilla black to dark gray, its mandible pale grayish white to yellowish (sometimes with a dark tip), and its legs and feed black to brown. Juveniles resemble adults but are overall duller and have some dusky scaling on the throat.<p>Subspecies S. a. propinquus has darker upperparts, breast, and belly than the nominate, and its throat is grayer. S. a. canigularis is generally darker than propinquus but its rufous cast is brighter than on both propinquus and the nominate. S. a. zamorae is generally darker than the nominate, with duller chestnut rump and uppertail coverts, a less whitish chin, and a brighter upper breast. S. a. albicollis has brighter and more rufescent upperparts than the other subspecies; its uppertail coverts are especially rich rufous. It has paler underparts than most others and a white throat. S. a. kempffi is the palest subspecies, with a grayer breast and belly and less reddish upper breast and back than the others. Its rump is the same color as its back. Some authors state that S. a. kunanensis has a somewhat greenish olive belly, some olive on its flight feathers, and a blackish tail but others find no difference between it and the nominate.

Tassonomia

The grey-throated leaftosser's taxonomy is unsettled. The International Ornithological Committee (IOC) and the Clements taxonomy assign it these seven subspecies:<p>BirdLife International's Handbook of the Birds of the World (HBW) does not recognize S. a. kunanensis. That subspecies might not be distinguishable from the nominate S. a. albigularis. <p>The grey-throated and rufous-breasted leaftosser (S. scansor) are sister species.<p>This article follows the seven-subspecies model.

Nome scientifico

Sclerurus albigularis

Autorità

Sclater, PL & Salvin, 1869

Ordine

Passeriformi

Famiglia

Furnariidae

Genere

Sclerurus

Areale e habitat

The grey-throated leaftosser has a disjunct distribution. The subspecies are found thus:<p>The grey-throated leaftosser inhabits evergreen forest, usually in foothills and lower montane areas, though in places it ranges both higher and lower. In the northeastern part of its range it approaches sea level and in Brazil it is strictly in the lowlands. In Costa Rica it occurs between 600 and 1,500 m (2,000 and 4,900 ft) of elevation, in Colombia between 500 and 2,200 m (1,600 and 7,200 ft), and in Ecuador mostly between 1,000 and 1,700 m (3,300 and 5,600 ft).

Migrazione

Specie stanziale

Comportamento

Comportamento migratorio: Specie stanziale.

Conservazione

Tendenza della popolazione: in diminuzione.

Tendenza della popolazione

in diminuzione