Scricciolo formichiero alilunghe

Identificazione

The long-winged antwren is 9 to 10.5 cm (3.5 to 4.1 in) long and weighs 8 to 10 g (0.28 to 0.35 oz). It is a smallish bird with a short tail. Adult males of the nominate subspecies M. l. longipennis have dark gray upperparts with a hidden white patch between the shoulders and white tips on the scapulars. Their wings are dark gray with white-tipped black coverts. Their tail is gray with white tips on the feathers. Their throat and upper breast are black; the rest of their underparts are a paler gray than the upperparts. Adult females have an ochraceous face, olive-brown upperparts, and dark grayish brown tail and wings. Their wing coverts and flight feathers have deep cinnamon edges. Their throat and breast are light buff. The rest of their underparts are mostly white with a gray tinge; their flanks are light gray with an olive tinge. Subadult males are like adult females with some light gray on the lower back and rump.<p>Males of the other subspecies of the long-winged antwren all have white tips on their facial feathers, and more black on the breast and slightly paler though variable underparts than the nominate. Females differ from the nominate and each other thus:

Tassonomia

The long-winged antwren was described by the Austrian ornithologist August von Pelzeln in 1868 and given its current binomial name Myrmotherula longipennis.<p>The long-winged antwren has these six subspecies:<p>Some authors have suggested that some subspecies deserve to be treated as separate species, and M. l. garbei was so treated by one early 20th century author. The long-winged antwren and the band-tailed antwren (M. urosticta) form a superspecies.

Nome scientifico

Myrmotherula longipennis

Autorità

Pelzeln, 1868

Ordine

Passeriformi

Famiglia

Thamnophilidae

Genere

Myrmotherula

Areale e habitat

The subspecies of the long-winged antwren are found thus:<p>The long-winged antwren inhabits the understorey to mid-storey of evergreen forest and mature secondary forest in the lowlands and foothills. It occurs primarily in terra firme forest and also in várzea, igapó, and transitional forest types. In elevation it occurs below 500 m (1,600 ft) in Colombia and Ecuador, up to 700 m (2,300 ft) in other lowlands, to 900 m (3,000 ft) in the Andean foothills, and to 1,100 m (3,600 ft) on the Venezuelan tepuis.

Migrazione

Resident species

Comportamento

The long-winged antwren is believed to be a year-round resident throughout its range.<p>The long-winged antwren's diet is mostly mostly insects and spiders. It forages singly, in pairs, or in family groups, and usually as part of a mixed-species feeding flock. It typically forages in dense vegetation mostly between about 2 and 8 m (7 and 30 ft) above the ground but will go as low as 1 m (3 ft) and as high as 14 m (50 ft). It forages mostly along thin and fairly open branches of understorey trees, especially those with larger leaves. It mostly gleans prey from live foliage and also takes prey from clusters of dead leaves, vine tangles, and along branches by gleaning, reaching, lunging, and with short sallies from a perch.<p>The long-winged antwren's breeding season has not been defined, but where it is known includes August to December. Its known nests were a deep cup of fungal fibers covered with dead leaves; they were hung from a branch at various heights above the ground up to about 12 m (40 ft). Both sexes provision nestlings. The clutch size, incubation period, time to fledging, and other details of parental care are not known.<p>The songs of the long-winged antwren subspecies differ, though the differences between adjoining ones are slight to moderate. The nominate subspecies' song is "a series of harsh upslurred notes...initially gains in intensity but nearly constant in pitch and pace" like "high, nasal 'suee' notes". The songs of M. l. zimmeri and M. l. garbei are "a deliberate series...each note dropping and then rising in pitch...while entire series rises in pitch" like "chuwey-chuwey-chuwey-chuwee-chuwee-chuwee". The songs of the other three subspecies vary slightly but generally are "a rapidly delivered series of abrupt downslurred notes that shorten slightly in length, mostly on same pitch except last notes rise". The most common call is "2–6 whistles, dropping in pitch, the number and length of notes variable among races and individuals".

Conservazione

Tendenza della popolazione

stable