White-eared Ground-Sparrow

The white-eared ground sparrow is about 18 cm (7.1 in) long and weighs about 42 g (1.5 oz). The sexes have the same plumage. Adults of the nominate subspecies have a mostly black head with white patches in front of the eye and on the ear coverts, a broken white eye-ring, a large yellow patch behind the ear coverts and on the sides of the neck, and a thin yellow line above the last. Their mantle is gray-brown and the rest of their upperparts, wings, and tail are olive-green. Their throat is black and a large black patch in the center of the breast sometimes connects to it. The sides of their breast and flanks are gray to white, their belly whitish, and their undertail coverts reddish to buffy. Subspecies M. l. nigrior is very similar to the nominate but has a larger black area on the breast that almost always is an extension of the black throat. Both sexes of both subspecies have a dark red-brown iris, a blackish bill, and pinkish legs and feet. Juveniles have a much less distinct facial pattern than adults. Their back is dark gray to brown with reddish tips on the feathers and their breast is grayish or brownish with wide black streaks. They have a gray-brown iris, a dark yellowish bill, and pinkish gray to pinkish brown legs and feet.

The white-eared ground sparrow has a disjunct distribution. Subspecies M. l. nigrior is the more northerly of the two. It is found in east-central Honduras and separately in north-central Nicaragua. The nominate is found in Costa Rica's Central Valley from far northeastern Puntarenas and western Alajuela provinces south to central San José Province. The species inhabits a variety of somewhat open landscapes including many that are human-modified. They include riparian forest, the edges of more extensive forest, coffee plantations, agricultural areas, and thickets in urban areas. Overall it ranges in elevation between 500 and 2,000 m (1,600 and 6,600 ft) but between 1,000 and 2,000 m (3,300 and 6,600 ft) in Costa Rica.

The white-eared ground sparrow feeds on small seeds, fruits, insects, and other arthropods. It has been observed feeding on other plant material and on waste or discarded human food like rice and crumbs. It forages in pairs and small family groups. It forages mostly on the ground, where between hops it moves leaf litter by kicking backwards with both feet simultaneously. It also feeds in shrubs and trees up to about 5 m (15 ft) above the ground.