One of the yellow-bellied trogons, the Green-backed Trogon, Trogon viridis, is widely found in Amazonia with disjunct populations in southeastern coastal Brazil and on the island of Trinidad. Until recently, these populations were classified as subspecies of White-tailed Trogon, though mitochondrial gene analysis and differences in voice and plumage served as evidence in the acceptance of this as a distinct species.
In addition to having a orange-yellow belly and under tail-coverts, males have black cheeks and throat with the rest of the head, neck, and upper chest black with iridescent purplish-blue. They have a pale blue orbital ring and a bluish white bill. The back is an iridescent green shifting to purplish-blue on rump and the upper tail is a bronze green, narrowly tipped with black. The white tips on the undertail are more extensive on the outer web giving the tail white edges with a dark center. Females are duller in color than males as the green and blue tones found in males are replaced by gray. Similar to White-tailed Trogons, the Green-backed Trogon has a very broad habitat range, frequently seen in second growth, forest edge as well as humid and dry forests up to 1,000 meters. The calls are a series of about 15-20 rapid but evenly spaced cow notes and differ from White-tailed Trogon whose call accelerates and often becomes louder towards the end. Nests in arboreal termitaria with both sexes excavating the nest which usually contains 2-3 eggs.