Streak-crowned Antvireo

The streak-crowned antvireo, a diminutive bird of the Thamnophilidae family, measures a mere 10 to 11 cm in length and tips the scales at a lightweight 15 to 17 grams. The males are adorned with a dark gray forehead, crown, and nape, all heavily streaked with grayish white. Their upperparts are a subtle grayish olive, and they boast a secretive white patch nestled between the scapulars. The females, on the other hand, display a rufous crown and nape, speckled with dark markings, and their wing coverts are tinged less black than their male counterparts.

Identification Tips

To identify the streak-crowned antvireo, look for the distinctive heavy streaking on the male's head and the white underparts with dark streaks. The female can be recognized by her rufous crown and nape and ochraceous breast and flanks. Both sexes have a dark grayish olive tail with narrow white tips.

Habitat

This species is a denizen of the evergreen forest understorey to mid-storey, preferring the lowlands and foothills. It can occasionally be found in mature secondary forests.

Distribution

The streak-crowned antvireo graces the Caribbean slopes of southeastern Honduras, Nicaragua, and most of Costa Rica, extending into Guanacaste Province.

Behaviour

The streak-crowned antvireo is a year-round resident, typically foraging alone or in pairs, often joining mixed-species feeding flocks. It forages between 1.5 and 8 meters above the ground, gleaning from foliage, vines, and thin branches, and occasionally making short sallies to capture prey.

Song & Calls

The song of the streak-crowned antvireo is a long series of notes that rise and fall in pitch and intensity. It also emits soft single or double whistles and a short 'chirr'.

Breeding

Breeding occurs from March to June in Costa Rica, with the bird constructing a cup nest suspended in a branch fork. The clutch typically consists of two eggs, incubated by both parents, who also share in brooding and provisioning the nestlings.

Diet and Feeding

Insects form the bulk of the diet, supplemented by other arthropods such as spiders. The antvireo feeds by gleaning from live foliage and making short flights to pluck prey from leaves.

Conservation status

The IUCN has classified the streak-crowned antvireo as Least Concern. Despite its somewhat restricted range and unknown population trends, it is generally considered fairly common to uncommon, with viable populations in several protected areas in Costa Rica.