Masked Gnatcatcher

The masked gnatcatcher (Polioptila dumicola) is a small songbird in the family Polioptilidae. It is found in Argentina, Bolivia, Brazil, Paraguay, and Uruguay. == Taxonomy and systematics == The masked gnatcatcher has three recognized subspecies, the nominate Polioptila dumicola dumicola, P. d. saturata, and P. d. berlepschi. The last subspecies differs in both plumage and voice from the other two and may represent a separate species. == Description == The masked gnatcatcher is 12 to 13 cm (4.7 to 5.1 in) long and weighs 5 to 7 g (0.18 to 0.25 oz), larger than most other gnatcatchers. The nominate male has a large black mask with a thin white line below it. Its forehead, crown, nape, and upperparts are blue-gray. Its tail is mostly black with white outer feathers. Its throat is pale gray fading to whitish on the belly. The nominate female does not have a mask but instead a black crescent down from the eye. Its upperparts are duller and not as bluish. P. d. saturata is darker than the nominate; it is slate gray overall that is lighter on the underside. The P. d. berlepschi male is paler than the nominate, dull gray rather than blue-gray above…