Silvered antbird
The silvered antbird is a passerine bird in the subfamily Thamnophilinae of the family Thamnophilidae, the "typical antbirds." It is found in Trinidad and every mainland South American country except Argentina, Chile, Paraguay, and Uruguay.
Taxonomy and systematics
The silvered antbird was formally described in 1788 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with the nuthatches in the genus Sitta and coined the binomial name Sitta naevia. Gmelin based his description of the "wall-creeper of Surinam," described and illustrated in 1764 by the English naturalist George Edwards in his Gleanings of Natural History. Edwards' specimen was preserved in spirits. It had been presented to the physician John Fothergill. The silvered antbird is now the only species in the genus Sclateria, introduced in 1899 by the American ornithologist Harry C. Oberholser. The genus name was chosen to honor the ornithologist Philip Sclater. The specific epithet is from the Latin naevius, meaning "spotted."The silvered antbird has these four subspecies:S. n. naevia S. n. diaphora Todd, 1913S. n. argentata S. n. toddi Hellmayr, 1924
Description
The silvered antbird is long and weighs. Adult males of the nominate subspecies S. n. naevia have a dark gray crown, nape, and upperparts. Their wings and tail are blackish gray with white tips on the wing coverts. Their face is mostly dark gray with a paler gray supercilium. Their underparts are mostly white with gray scalloping that is lightest on the throat. Their flanks, crissum, and underwing coverts are gray. Adult females have the same pattern as males, but are grayish brown, whereas males are gray and have cinnamon tips on the wing coverts. Subadult males look like adult females.Males of subspecies S. n. argentata have almost white underparts with faint light gray mottling on the breast and flanks and a paler gray crissum than the nominate. Females have grayer upperparts than the nominate; their underparts vary from white with buffy brown sides and vent area to deep buff with browner sides and vent. S. n. toddi is intermediate between the nominate and argentata. S. n. diaphora males have small white dots, rather than white tips, on their wing coverts, and mostly gray underparts with a few thin white streaks on the breast. Females have ochraceous tawny underparts with little to no mottling.
Distribution and habitat
The subspecies of the silvered antbird are found thus:S. n. naevia: Trinidad, eastern Venezuela, the Guianas, and northeastern Brazil, mostly south of the AmazonS. n. diaphora: drainage of the lower Rio Caura in Venezuela's Bolívar stateS. n. argentata: southeastern Colombia and southern Venezuela south through eastern Ecuador, eastern Peru, and western Amazonian Brazil into northwestern and eastern BoliviaS. n. toddi: south-central Amazonian Brazil south of the Amazon from the Rio Madeira and Teles Pires to the Rio TocantinsThe silvered antbird inhabits the floor and understorey of tropical evergreen forest, primarily várzea and igapó, along streams, terra firme and in swampy areas within the forest. It favors areas with vine tangles, branches, and vegetation that overhang the water's edge. In Trinidad and Suriname, it also occurs in mangrove swamps, and Ecuador and Peru, found in Mauritia flexuosa palm swamps. In elevation, it reaches in Venezuela and Colombia, in Ecuador, and in Peru.