Trogons and Quetzals Trogons include Quetzals which are also in the order "trogoniformes"/family "trogonidae")

TROGONIDAE (Trogans and Quetzals) live in the tropics across the globe from Africa to Asia to America. Their scientific name refers to their habit of gnawing out nesting holes in trees. They are the only animals with heterodactyl feet (toes 3 and 4 forward and 1 and 2 back). Males have different, more colourful plumage than females.

Sumatran Trogon
Sumatran Trogon
Sumatran Trogon
The SUMATRAN TROGON, Apalharpactes mackloti, comes from the western part of the island of Sumatra, Indonesia. It is closely related to the Blue-tailed Trogon from the island of Java.
  
White-tailed Trogon
White-tailed Trogon male
White-tailed Trogon male
The WHITE-TAILED TROGON, Trogon chionurus, comes from the northern part of South America and north to Panama. The "white-tailed" part is the underside of the greenish tail. The male, above, has an iridescent green back and outer tail and resembles the Green-backed Trogon (Trogon viridis) except for his white undertail.
White-tailed Trogon female
White-tailed Trogon
White-tailed Trogon female
The female White-tailed Trogon, above, has a grey head, chest, back and wings instead of the iridescent dark blue and green of the male. Her yellow belly is much paler than his.
  
Black-headed Trogon
Black-headed Trogon
Black-headed Trogon
The BLACK-HEADED TROGON, Trogon melanocephalus, looks similar to the White-tailed and has a patterned white under-tail but also has blue eye-rings and a much stronger and more extensive yellow belly. It is native from Mexico to Costa Rica. Photos taken in Costa Rica by Alexandra Makhnina.
  
Golden-headed Quetzal
Golden-headed Quetzal
Golden-headed Quetzal
The GOLDEN-HEADED QUETZAL, Pharomachrus auriceps, comes from mountain forests of northern South America.
The male is iridescent green with a bright red belly and black undertail (distinguishing him from the similar Crested Quetzal with white undertail).
His head is not so much golden as shiny light red and green. The female has a grey head and chest with duller green throat and wings and duller red belly.