Black-cheeked warbler

The black-cheeked warbler (Basileuterus melanogenys) is a species of bird in the family Parulidae, the New World warblers. It is found in Costa Rica and Panama.

The black-cheeked warbler is about 13.5 cm (5.3 in) long and weighs an average of about 12 g (0.42 oz). The sexes have the same plumage. Adults of the nominate subspecies B. m. melanogenys have a chestnut crown, a white or pale yellowish supercilium, and a thin black line between them on an otherwise blackish face. The sides of their nape are sooty blackish and the rest of the nape is dark brownish gray or olive. Their back, wings, and tail are dusky brownish gray and their rump and uppertail coverts are olive. Their throat is whitish, their breast grayish, their flanks olive, and the center of their belly and their undertail coverts are buffy white. Juveniles have a sooty brown head with an olive-tinged supercilium. Their upperparts are browner than their head; their greater and median upperwing coverts have buffy tips that show as two wing bars. Their underparts are mostly pale yellowish with a brownish wash on the breast, sides, and flanks. Subspecies B. m. eximius has paler and grayer upperparts than the nominate with paler and more whitish underparts and grayer flanks. B. m. bensoni has gray upperparts and a darker breast and whiter rest of the underparts than the nominate. All subspecies have a dark brown iris, a dusky black maxilla, a pink mandible, and pale brownish white legs and feet.