Puerto Rican Euphonia

The Puerto Rican euphonia is about 10 to 12 cm (3.9 to 4.7 in) long and weighs about 12 to 16 g (0.42 to 0.56 oz). The species is sexually dimorphic. Adult males have an orange-yellow forehead that is separated from the forecrown by a narrow dark blue strip. Their crown and nape are sky blue that extends forward from the latter under the ear coverts. The rest of their head is dark violet blue. Their back is black with a blue gloss; it appears blue in direct light. Their rump and uppertail coverts are bright yellow. Their tail and wing coverts are black with bluish reflections. Their flight feathers are black with thin blue edges. Their throat is yellow and the rest of their underparts dull orange yellow with a slight brownish tinge on the crissum. Adult females' foreheads can be red, yellow, or yellowish olive green. Their crown and nape are blue that curves forward like the male's. The rest of their head is mostly olive green with a yellowish chin and throat. Their back, wings, and tail are olive green. Their underparts are dull olive yellow. Both sexes have a dark brown iris, a black maxilla, a blackish mandible with a grayish base, and dark gray to black legs and feet.

The Puerto Rican euphonia is found throughout the island of Puerto Rico. It inhabits a variety of landscapes including the interior and edges of evergreen, deciduous, and secondary forests. It especially favors areas heavy with mistletoe (Loranthaceae). In elevation it ranges from sea level to the island's highest point at about 1,300 m (4,300 ft).

The Puerto Rican euphonia feeds on small fruits, almost entirely those of mistletoe. It includes smaller amounts of other fruits and also small arthropods in its diet. It feeds mostly in the forest canopy. It forages mostly in pairs and occasionally joins mixed-species feeding flocks.