Yellow-faced Grassquit

The Yellow-faced Grassquit, Tiaris olivaceus, is a diminutive passerine, a member of the tanager family Thraupidae. It is the sole representative of the genus Tiaris. Exhibiting sexual dimorphism, the male is distinguished by an olive-green back, a striking yellow throat, and a black face and breast, while the female is more subdued in coloration.

Identification Tips

Adult males are identifiable by their olive-green dorsum and the contrasting black of their face and breast, punctuated by a bright yellow throat, supercilia, and a spot below the eye. Females and juveniles are more muted, with females sporting a paler grey underbelly and a less pronounced yellow facial pattern.

Habitat

This species thrives in semi-open landscapes, such as weedy fields, pastures, and roadside scrub, up to elevations of 2,300 meters. It tends to avoid arid grasslands, preferring areas where grasses grow tall.

Distribution

The Yellow-faced Grassquit is native to a broad range stretching from central Mexico to northern Ecuador and north-western Venezuela, as well as the Greater Antilles and adjacent isles. It is a resident bird, though some post-breeding dispersal is noted.

Behaviour

A sociable bird, the Yellow-faced Grassquit may form loose flocks, often mingling with other tanagers and emberizids. It is not uncommon to observe adult males congregating to sing from a shared perch.

Song & Calls

The call of this species is a soft buzzing trill, while its song consists of a series of high, rapid trills. The song, though melodious, is quite subdued and best heard from close quarters.

Breeding

Breeding primarily occurs in the summer, with the male displaying a wing-vibrating courtship behavior accompanied by his song. The female constructs a globular nest with a side entrance, typically situated low in grass or shrubs. Clutches usually contain two to three speckled eggs.

Diet and Feeding

The diet is predominantly grass seeds, supplemented with other seeds, berries, and some insects. Foraging occurs both on the ground and among foliage, with animal prey hunted in a manner reminiscent of New World warblers.

Conservation status

The Yellow-faced Grassquit is classified as Least Concern by the IUCN, with populations benefiting from deforestation, leading to range expansion and increased numbers.