Rusty-breasted nunlet

The rusty-breasted nunlet (Nonnula rubecula) is a species of near-passerine bird in the family Bucconidae, the puffbirds, nunlets, and nunbirds. It is found in Argentina, Brazil, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Venezuela, and possibly French Guiana.

The rusty-breasted nunlet is 14 to 16 cm (5.5 to 6.3 in) long and weighs 17 to 20 g (0.60 to 0.71 oz). The subspecies vary in structure and color from each other. In general, the more northerly subspecies have a longer and narrower bill and a shorter tail than the more southerly ones.

The nominate subspecies has what amounts to two or three color morphs. Some members of it have plain dark gray-brown upperparts and wings. Their lores are rufous and they have a whitish band from the lores that joins a white ring around the eye. Their tail is dark brown. Their throat, breast, and flanks are brown with a reddish tinge and the abdomen is whitish. Other members of the nominate are paler and grayer, especially on the crown, but in the southeast are a darker brown with a warmer brown tail. Some have a bright orange-rufous (instead of brown) throat, breast, and flanks.

N. r. tapanahoniensis has a very gray crown and a cinnamon tinge to the vent. N. r. duidae has a rufous chin. N. r. interfluvialis has a grayer tail and N. r. simulatrix a darker tail than the others. N. r. simplex is drab and dark while N. r. cineracea has warmer brown underparts.