The Yellow-winged Vireo, Vireo carmioli, is a small passerine

Passerine

A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...

 bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

. It is endemic to the highlands of Costa Rica

Costa Rica

Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....

 and western Panama

Panama

Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...

.

This vireo

Vireo

The vireos are a group of small to medium-sized passerine birds restricted to the New World. They are typically dull-plumaged and greenish in color, the smaller species resembling wood warblers apart from their heavier bills...

 occurs from 2000 m to the timberline in the canopy of mountain forest, sometimes feeding in undergrowth or tall second growth. The small cup nest is built in the fork of a small branch 3–20 m high in a tree or scrub and the clutch is two dark-spotted white eggs. Both sexes construct the nest, incubate the eggs and feed the young.

The adult Yellow-winged Vireo is 11.5 cm in length and weighs 13 g. It has olive-green upperparts and blackish wings with two yellow wing bars. There is a yellowish supercilium

Supercilium

The supercilium is a plumage feature found on the heads of some bird species. It is a stripe which runs from the base of the bird's beak above its eye, finishing somewhere towards the rear of the bird's head. Also known as an "eyebrow", it is distinct from the eyestripe, which is a line which runs...

 which joins the interrupted white eye ring. The throat is white, and the underparts are otherwise pale yellow with some olive on the flanks. Young birds are browner above and have very pale yellow underparts.

Yellow-winged Vireos feed on spider

Spider

Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...

s and insect

Insect

Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...

s gleaned

Gleaning (birds)

Gleaning is a term for a feeding strategy by birds in which they catch invertebrate prey, mainly arthropods, by plucking them from foliage or the ground, from crevices such as rock faces and under the eaves of houses, or even, as in the case of ticks and lice, from living animals. This behavior is...

 from tree foliage, and also eat small fruits. They will join mixed-species feeding flock

Mixed-species feeding flock

A mixed-species feeding flock, also termed a mixed-species foraging flock, mixed hunting party or informally bird wave, is a flock of usually insectivorous birds of different species, that join each other and move together while foraging...

s, or accompany Flame-throated Warbler

Flame-throated Warbler

The Flame-throated Warbler, Oreothlypis gutturalis, is a small New World warbler. It is sometimes placed in the genus Vermivora.-Life history:...

s.

The Brown-capped Vireo has a nasal nit call and the song is a high slurred viree chichu chuyee; viree viree cheeyu; viree witchum vireee.