About Myrmotherula schisticolor (Lawrence, 1865)
The slaty antwren (Myrmotherula schisticolor, first described by Lawrence in 1865) measures 9 to 12 cm (3.5 to 4.7 in) in length and weighs 8.5 to 10 g (0.30 to 0.35 oz). It is a smallish bird with a short tail.
For the nominate subspecies, adult males are mostly dark gray, with a hidden white patch between the shoulders. Their tail is dark gray, with thin white edges along the feathers. Their wings are dark gray, with white tips on the coverts. Their throat and upper breast are black, and their crissum is dark gray with whitish feather tips. Adult nominate females have grayish olive upperparts and a browner tail. Their wings are browner than their back, with rufous edges on the coverts. Their throat is pale cinnamon, their sides and flanks are olive-brown, and their remaining underparts are tawny-tinged cinnamon that becomes yellowish brown on the crissum.
Males of the subspecies M. s. sanctaemartae are much paler than nominate males, with browner edging on the flight feathers. Black coloring on their underside is restricted to the throat and the center of the uppermost breast. Females of this subspecies have much grayer upperparts and more yellowish-brown underparts than nominate females.
Males of subspecies M. s. interior are intermediate in appearance between nominate males and M. s. sanctaemartae males. Their white shoulder patch is small. Females are darker and more blue-gray than M. s. sanctaemartae females, with tawny-tinged cinnamon underparts.
The slaty antwren has a disjunct distribution, and the nominate subspecies is the most widely distributed. One population of the nominate subspecies occurs from Chiapas in extreme southeastern Mexico, through Guatemala, southern Belize, and the Caribbean slope of Honduras, into northern Nicaragua. A second nominate population occurs mostly on the Pacific slope through Costa Rica, and is found sporadically through Panama. A third nominate population extends from Colombia's Western Andes, south along most of Ecuador's Pacific slope.
Subspecies M. s. sanctaemartae is found in Colombia's isolated Sierra Nevada de Santa Marta, in the Serranía del Perijá along the Colombian-Venezuelan border, and in the Venezuelan Andes and Coastal Ranges. Subspecies M. s. interior is found on the western slope of Colombia's Central Andes, in Colombia's Eastern Andes, and south along the eastern Andean slope through Ecuador and Peru, almost to the Bolivian border.
The slaty antwren lives in a variety of moist forested landscapes, and generally occurs at higher elevations than most other species in its genus. Across most of its range, it inhabits foothill and montane evergreen forest, where it prefers cloudforest, and nearby secondary woodland. Along the Pacific slope from Costa Rica south, and on the Caribbean slope in Venezuela, it occurs in semi-humid forest. In Central America, it is generally found between sea level and 1,250 m (4,100 ft), though it reaches 2,000 m (6,600 ft) in Costa Rica. In Colombia, its elevation ranges from 1,000 to 2,300 m (3,300 to 7,500 ft). In western Ecuador it mostly occurs between 400 and 1,450 m (1,300 and 4,800 ft), and in eastern Ecuador between 900 and 1,700 m (3,000 and 5,600 ft).
