The black-faced grassquit (Melanospiza bicolor) is a small bird. It is recognized as a 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. A male black-faced grassquits is around 10 cm (3.9 in) long and weighs approximately 10 g (0.35 oz). It has a short conical black bill, a black head and breast with an olive green back. Females and immature birds have dull olive-grey upperparts and head, and paler grey underparts becoming whiter on the belly.
The Black-faced Grassquit occurs from northern South America through the West Indies, where it is a common resident species in Puerto Rico (Oberle 2018, Raffaele and others 1998), Culebra (Ventosa-Febles and others 2005), and Vieques (Gemmill 2015). This species is common in urban areas and open areas with grasses and shrubs including gardens, road edges, and forest clearings (Oberle 2018, Raffaele and others 1998). The atlas fieldwork yielded a total of 861 records within 400 hexagons or 84 percent of the 479 total hexagons (see map). Of the 400 hexagons where this species was found, breeding met the atlas definition of confirmed in 20 percent (78) of the hexagons, probable in 50 percent (199), and possible in 31 percent (123) (see map). Black-faced Grassquit distribution. The map shows the highest breeding code by hexagon and overlaying the ecological life zones in Puerto Rico. Note: percentages may not total 100 due to rounding.
Previously published reports indicate that the Black-faced Grassquit breeds year-round (Raffaele and others 1998). Atlas results show that the breeding season for this species extends throughout the year, but it is most active from March through 285Black-faced Grassquit/Gorrión NegroJune, with a peak in May (see chart). Results show that the Black-faced Grassquit breeds in all ecological life zones but mostly within the subtropical moist, subtropical dry, and subtropical wet forest life zones (59, 21, and 20 percent of the hexagons, respectively), while breeding activity has also been reported for one hexagon in the subtropical rain forest life zone (see table and map).
The population of the Black-faced Grassquit is listed as a species of least concern by the IUCN (BirdLife International 2018). Locally, this species is not listed in any of the threatened categories used by PRDNER and USFWS. In Puerto Rico, the Black-faced Grassquit has a protected habitat in land of 12 percent or 1102 km2 of the total area covered by the hexagons where evidence of breeding was found for this species (9565 km2). Note this area is larger than the total terrestrial area of the island because coastal hexagons and those hexagons covering small cays include a portion of water.