Rufous-crowned Greenlet

The rufous-crowned greenlet is about 12.5 cm (4.9 in) long and weighs 9 to 12 g (0.32 to 0.42 oz). The sexes have the same plumage. Adults have a bright chestnut-brown forehead and crown and mottled grayish black ear coverts. Their nape, upper back, and shoulders are olive-green and their lower back and rump are a brighter green. Their wings are dull grayish black with thin greenish edges on the outer webs of the primaries and secondaries and yellow-green edges on the inner webs of the tertials. Their tail is grayish green with brighter greenish edges on the feathers' outer webs. Their throat is dull pale gray, their upper breast yellowish gray, their lower breast dull yellow, their flanks and belly a brighter yellow, and their vent dull yellowish. They have a dark reddish brown iris, a dull blackish maxilla, a gray to dusky pink mandible, and grayish legs and feet. Immatures are similar to adults but with a more olivaceous back and brighter underparts.

The rufous-crowned greenlet is found in southeastern Brazil from southern Mato Grosso do Sul south into Rio Grande do Sul, across eastern Paraguay, and into northeastern Argentina's Misiones Province. In addition, the South American Classification Committee has unconfirmed reports from Bolivia. It inhabits moist to humid forest, woodlands, scrublands, and mature secondary forest. In elevation it ranges from sea level to 1,800 m (5,900 ft).

The rufous-crowned greenlet feeds on mostly on arthropods and includes some fruits its diet. It forages mostly in the forest canopy but will feed all the way down to near the ground. It typically forages singly, in pairs, or in family groups and regularly joins mixed-species feeding flocks. It takes food mostly by gleaning while perched and only rarely takes insects in mid-air.