between the genus Semnornis (which contains the toucan barbet) and toucans was found. The two lineages were more closely related to each other than even Semnornis and the other New World barbets. This led to a breakup of the barbet family, and the separate lineages are now considered to be distinct families; the toucan barbet is, together with the prong-billed barbet, now placed into the family Semnornithidae. An alternative arrangement is to combine all the barbets and the toucans into a single family, which due to priority would be the toucan family Ramphastidae. The two described subspecies are the nominate race, found in Ecuador, and the subspecies S. r. caucae from Columbia. S. r. caucae, named for Cauca in Columbia, was described in 1941 by Swedish ornithologist and explorer Nils Gyldenstolpe. Description The toucan barbet is a medium-sized robust barbet, of long and weighing . The beak is robust with a yellow maxilla and a light green mandible, both with dark ends. It is pronged at the end, though the prongs are not noticeable in the field. The plumage is colourful and includes a black crown, "mask", and thin cervical collar. The species has long occipital feathers and a conspicuous white stripe behind the eyes, which has a bright red-colored iris. The nape of the neck is golden-brown and becomes yellow towards the rump. The throat, upper breast, and sides of the nape are grayish-blue. The lower breast and middle belly are bright red, while the lower belly is yellowish green. The wings and tail are grey. The subspecies S. r. caucae is very similar to the nominate race, but has less extensive red on the breast. Both sexes are almost identical except for the female's plumage being slightly less bright, and the female lacks the tuft on the black plumage of the nape. Immature birds are duller than adults, and do not develop prongs until they are 4 months old. Habitat and distribution The species is native to the humid forests of the western Andes, from the Andean slopes of northwest Ecuador to southwest Colombia, at altitudes of . It uses all forest strata, showing some preference for the upper canopy of the forest () and the subcanopy (). The species also uses secondary forest and forest-edge habitats. Evidence suggests that these birds are very specific in choosing trees for nesting. It usually prefers old trees in the family