White-bellied dacnis

The white-bellied dacnis was formally described in 1852 with the binomial Pipraeidea albiventris.^[4] For a time it was assigned its own genus Hemidacnis but has been assigned to Dacnis since the middle of the twentieth century.^[5] The species is monotypic.^[2]

The white-bellied dacnis is 10 cm (3.9 in)^[5] to 12 cm (4.7 in)^[6] long. It weighs 11 to 11.5 g (0.39 to 0.41 oz). It has a short, conical, pointed bill. The species is sexually dimorphic. Adult males have a bright cobalt-blue head with a triangular black mask from the lores through the eye onto the ear coverts. Their upperparts are mostly cobalt-blue withe black scapulars. Their wing's lesser coverts are cobalt-blue and the median and greater coverts black with wide cobalt-blue edges. Their flight feathers are black with cobalt-blue edges. Their tail is black. Their throat and breast are cobalt-blue, their belly to undertail coverts white, and their flanks light gray with light blue spotting. Adult females have a dull olive head with darker lores. Their back is dull olive that becomes greener on the rump. Their wing coverts are olive brown and the flight feathers olive with olive-brown edges. Their tail is dusky. Their throat is grayish white and their underparts mostly greenish yellow with a yellower center to the belly. Both sexes have a blackish bill and gray legs and feet. Males have a golden yellow iris and females' are light brown to grayish brown.^[5]

The white-bellied dacnis is primarily a bird of the far western Amazon Basin.^[5] It is found across the southeastern third of Colombia south intermittently through eastern Ecuador into northeastern Peru as far as central Ucayali Department with a few reports further south.^[6][7][8] From Colombia and Peru its range extends northeast across far western Brazil's Acre, Amazonas, and Roraima states into southwestern Amazonas state in southern Venezuela. There are also a few records in central and eastern Amazonian Brazil.^[9][10]

The white-bellied dacnis "appears to prefer somewhat marginal habitats". These include white-sand forest and savanna, well-weathered terra firme, and campina.^[5] In elevation it reaches 500 m (1,600 ft) in Colombia, 300 m (1,000 ft) in Ecuador, 200 m (700 ft) in Venezuela, and 400 m (1,300 ft) in Brazil.^{[6][7][9][10]}

The IUCN originally in 1988 assessed the white-bellied dacnis as Threatened, then in 1994 as Near Threatened, and since 2000 as being of Least Concern. It has a large range; its population size is not known but is believed to be stable. No immediate threats have been identified.^[1] It is considered "uncommon and seemingly seasonal" in Colombia, "rare and very local" in Ecuador, "rare [and] poorly known" in Peru, "rare" with only "scattered records" in Venezuela, and "uncommon to rare" in Brazil.^{[6][7][8][9][10]} It has "a high degree of sensitivity to human disturbance relative to other Neotropical birds" but does occur in several protected areas.^[5]