Rufous-bellied Euphonia

The rufous-bellied euphonia is about 10 cm (3.9 in) long and weighs 13 to 18 g (0.46 to 0.63 oz). It is a smallish euphonia with a stout bill. The species is sexually dimorphic. Adult males of the nominate subspecies have a dark steel-blue head, throat, chest, and upperparts. Their flight feathers and tail are dusky with a steel-blue tinge and steel-blue feather edges. They have a patch of golden-yellow pectoral feathers that is usually hidden under the wing. Their underparts below the chest are mostly orange that is somewhat golden-yellow on the sides. Voice: The rufous-bellied euphonia's song is described as "a disjointed, mechanical series of pure whistles, quiet liquid sounds, and short warbles, with various phrases given before any is repeated". Its calls include "a rapid, deep, ringing chatter: tcheetcheetcheetchee and a liquid whit".