The Black-faced Grassquit (Tiaris bicolor) is a small tanager closely related to Darwin’s finches. It breeds in the West Indies except Cuba, on Tobago but not Trinidad, and along the northern coasts of Colombia and Venezuela.
Adult Black-faced Grassquits are 10.2 cm long and weighs 10.5 g. They have a short conical black bill with an obvious curve to the culmen. The male is olive green above, paler grey-olive below, and has a black head and breast.
Female and immature Black-faced Grassquits have dull olive-grey upperparts and head, and paler grey underparts becoming whiter on the belly. [Wikipedia]
Black-face Grassquits specialize in eating grass seeds, and often forages in grassy lawns and fields. On smaller and lighter grasses, they may bend the seed head to the ground and forage on it in that manner. This niche of feeding on grass seeds while still on the stems is also used by Sporophila Seedeaters, and in the Old World by various Lonchura Mannikins. Interestingly enough some Black-faced Grassquits feed on cactus fruit in the Netherland Antilles, as do the Cactus-finches on the Galapagos. [Neotropical Birds]