Puffbird
The puffbirds and their relatives in the near passerine family Bucconidae are tropical tree-dwelling insectivorous birds that are found from South America up to Mexico. Together with their closest relatives, the jacamars, they form a divergent lineage within the order Piciformes, though the two families are sometimes elevated to a separate order Galbuliformes. Lacking the iridescent colours of the jacamars, puffbirds are mainly brown, rufous or grey, with large heads, large eyes, and flattened bills with a hooked tip. Their loose, abundant plumage and short tails makes them look stout and puffy, giving rise to the English name of the family. The species range in size from the rufous-capped nunlet, at 13 cm (5.1 in) and 14 g (0.49 oz), to the white-necked puffbird, at up to 29 cm (11 in) and 106 g (3.7 oz).
Taxonomy and naming
Puffbirds get their common name from their fluffy plumage. In Spanish, they have been nicknamed bobo "dummy" from their propensity to sit motionless waiting for prey. American naturalist Thomas Horsfield defined the Bucconidae in 1821. The family was classified as part of the Piciformes by Alexander Wetmore in his work A Systematic Classification for the Birds of the World (1930, revised in 1951 and 1960). The placement of the combined puffbird and jacamar lineage was in question, with some bone and muscle features suggesting they may be more closely related to the Coraciiformes. However, analysis of nuclear DNA in a 2003 study placed them as sister group to the rest of the Piciformes, also showing that the groups had developed zygodactyl feet (two toes facing forward and two aft) before separating. Per Ericson and colleagues, in analysing genomic DNA, confirmed that puffbirds and jacamars were sister groups and their place in Piciformes. The lineage is sometimes elevated to order level as Galbuliformes, first proposed by Sibley and Ahlquist in 1990.