page_title: Trogon
section_title: Morphology and flight
hierarchical_section_title: Trogon / Morphology and flight
caption_attribution_description: English: Skull of Trogon collaris puella https://archive.org/details/catalogueofspeci00shar pg. pterygoid mpl.p maxillo-palatine process pl. palatine bpg.p. basipterygoid process
context_page_description: The trogons and quetzals are birds in the order Trogoniformes which contains only one family, the Trogonidae. The family Trogonidae contains 46 species in seven genera. The fossil record of the trogons dates back 49 million years to the Early Eocene. They might constitute a member of the basal radiation of the order Coraciiformes or be closely related to mousebirds and owls. The word trogon is Greek for "nibbling" and refers to the fact that these birds gnaw holes in trees to make their nests.
  Trogons are residents of tropical forests worldwide. The greatest diversity is in the Neotropics, where four genera, containing 24 species, occur. The genus Apaloderma contains the three African species. The genera Harpactes and Apalharpactes, containing twelve species, are found in southeast Asia.
  They feed on insects and fruit, and their broad bills and weak legs reflect their diet and arboreal habits. Although their flight is fast, they are reluctant to fly any distance. Trogons are generally not migratory, although some species undertake partial local movements. Trogons have soft, often colourful, feathers with distinctive male and female plumage.
context_section_description: The trogons as a family are fairly uniform in appearance, having compact bodies and long tails (very long in the case of the quetzals), and short necks. Trogons range in size from the 23 cm, 40 gram scarlet-rumped trogon to the 40 cm, 210 gram resplendent quetzal (not including the male quetzal's 3-foot-long (0.91 m) tail streamers). Their legs and feet are weak and short, and trogons are essentially unable to walk beyond a very occasional shuffle along a branch. They are even incapable of turning around on a branch without using their wings. The ratio of leg muscle to body weight in trogons is only 3 percent, the lowest known ratio of any bird. The arrangement of toes on the feet of trogons is also unique among birds, although essentially resembling the zygodactyl's two forward two backward arrangement of parrots and other near-passerines, the actual toes are arranged with usually inner hallux being the outer hind toe, an arrangement that is referred to as heterodactylous. The strong bill is short and the gape wide, particularly in the fruit eating quetzals, with a slight hook at the end. There is also a notch at the end of the bill and many species have slight serrations in the mandibles. The skin is exceptionally tender, making preparation of study skins difficult for museum curators. The skeletons of trogons are surprisingly slender, particularly the skulls which are very thin. The plumage of many species is iridescent, although most of the Asian species are not. The African trogons are generally green on the back with red bellies. The New World trogons similarly have green or deep blue upperparts but are more varied in their lowerparts. The Asian species tend towards red underparts and brown backs.
  The wings are short but strong, with the wing muscle ratio being around 22% of the body weight. In spite of the strength of their flight, trogons do not fly often or for great distances, generally flying no more than a few hundred metres at a time. Only the montane species tend to make long-distance flights. Shorter flights tend to be direct and swift, but longer flights are slightly undulating. Their flight can be surprisingly silent (for observers), although that of a few species is reportedly quite noisy.
caption: Skull of a trogon showing the presence of a basipterygoid process (bpg.p.) and a schizognathous palate
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