About Trogon viridis Linnaeus, 1766
This relatively large trogon measures 28 to 30 centimetres (11 to 12 inches) in length. Like most trogons, it shows strong sexual dimorphism. Males have dark blue head and upper breast (appearing blackish in poor light), a green back, and orange-yellow lower underparts. Their wings are black with white vermiculation. The undertail is patterned black and white: each feather has a broad black base, and a broad white tip and outer edge. Males also have a complete pale bluish eye-ring. Females of this species resemble males, but have a grey back, head, and breast, and distinct black-and-white barring that is mainly found on the outer webs of each tail feather. The similar smaller violaceous trogon can be distinguished from this species: male violaceous trogons have a yellow eye-ring, while female violaceous trogons have an incomplete white eye-ring, and male violaceous trogons also have barring on the undertail. Green-backed trogons and white-tailed trogons have no overlapping distribution, but can be separated by their undertail pattern. Unlike the green-backed trogon, male white-tailed trogons only have a very narrow black base to each feather, making the undertail appear almost entirely white, while female white-tailed trogons have black-and-white barring mainly on the inner webs of each feather, which can be difficult to see. Male white-tailed trogons also have a bluer rump than green-backed trogons. The song of the green-backed trogon is made up of around 20 "cow" notes that start slow and accelerate toward the end. The song is slower than that of the white-tailed trogon, and higher pitched than that of the black-tailed trogon. The green-backed trogon occurs in tropical humid forests of South America; its range covers the Amazon basin, the Guiana Shield, Trinidad, and the Atlantic Forest in eastern Brazil. It is a resident species of humid tropical forests, and is typically the most common trogon throughout its range. Green-backed trogons typically perch upright and remain motionless. Although their flight is fast, they are reluctant to fly long distances. Their broad bills and weak legs reflect their diet and arboreal habits. They feed mainly on small fruit, and supplement their diet with arthropods and lizards. They consume more arthropods and lizards in the dry season when fruit is scarce, but even during the dry season they remain among the most frugivorous trogons in their range. Because of their frugivorous diet, they are seen less often at mixed-species feeding flocks than other trogons. This species nests in termite nests or cavities in rotten trees. If not always, the nest is usually built by the female, who excavates an upward-sloping tunnel that ends in a breeding chamber. The nesting season is apparently mainly during the summer months between June and August. A typical clutch has two or three white eggs. Incubation lasts 16 to 17 days, and chicks fledge two weeks after hatching.
