Averla formicaria guance argentate

Identificazione

The silvery-cheeked antshrike is about 14 cm (5.5 in) long. Both sexes have a crest. Adult males have a black forehead, crest, front of the face, throat, and breast center. The rest of their head and underparts are grayish white. Their back is brown. Their wings are black with white tips on the coverts and cinnamon edges on the flight feathers. Their tail is black with white spots and feather tips. Adult females have a rufous forehead, crest, and crown. The rest of their head and their underparts are pale buffy brown. The back is brown like the male's. Their wings are brown with white tips on the coverts and cinnamon edges on the flight feathers. Their tail is rufous-brown with no white.

Tassonomia

The silvery-cheeked antshrike was originally described as Turdus cristatus. and was later transferred to genus Sakesphorus. Its transfer to the new genus Sakesphoroides was proposed in 2010 based on the species' distinctive morphology. It uniqueness was confirmed by a genetic study published in 2010. Based on that study, the South American Classification Committee of the American Ornithological Society, the International Ornithological Congress, and the Clements taxonomy quickly moved the silvery-cheeked antshrike to Sakesphoroides. However, as of December 2023 BirdLife International's Handbook of the Birds of the World retained it in Sakesphorus.<p>The silvery-cheeked antshrike is the only member of genus Sakesphoroides and has no subspecies.

Nome scientifico

Sakesphoroides cristatus

Autorità

(Wied-Neuwied, M, 1831)

Ordine

Passeriformi

Famiglia

Thamnophilidae

Genere

Sakesphoroides

Areale e habitat

The silvery-cheeked antshrike is found in northeastern Brazil from Ceará and central and western Rio Grande do Norte south through southeastern Piauí, western Pernambuco, and inland Bahia into central Minas Gerais. It inhabits the understorey to mid-storey of deciduous forest and arid caatinga, and also the ecotone between deciduous and ridgetop evergreen forest. It favors areas where the forest has a closed canopy, such as mata-de-cipó. In elevation it ranges from sea level to 1,100 m (3,600 ft).

Migrazione

Resident species

Comportamento

The silvery-cheeked antshrike is believed to be a year-round resident throughout its range.<p>The silvery-cheeked antshrike's diet includes insects and other arthropods; it favors ants and termites, and during the breeding season caterpillars. It mostly forages singly or in pairs and sometimes as a member of a mixed-species feeding flock. It typically forages from the ground to 2 m (7 ft) above it but also as high as 10 m (30 ft). It captures prey mostly by reaching up from the ground or a perch to glean from leaves, vines, and branches. It also pounces onto prey from a perch to the ground, and less often hitches its way up branches and through vine tangles.<p>Nothing is known about the silvery-cheeked antshrike's breeding biology.<p>The silvery-cheeked antshrike's song is a "short series of chopped, nasal notes, accelerating and trailing off to a growling sound" and lasting three to four seconds. Its calls include a " deep clear whistle, and [a] more abrupt clear note sometimes repeated rapidly 3–4 times".

Conservazione

Tendenza della popolazione

declining