Trogons

Trogons are about 35 species of beautiful arboreal birds that constitute the family Trogonidae. Trogons have a number of peculiar features in their morphology, and are not thought to be closely related to any other groups of living birds. This is why their family is the only one in the order Trogoniformes.

Species of trogons occur throughout the tropical and subtropical parts of the world, a biogeographic distribution known as pan-tropical. Most species of trogons occur in Central and especially South America , with three species in Africa , and 11 species in Asia . Most trogons live in dense forests and woodlands, and are unobtrusive birds that tend to sit and fly quietly and are not often seen. Trogons do not undertake long-distance migrations, although some species may make local, seasonal movements.

Trogons range in body length from 9-14 in (23-34 cm). The bill of trogons is short and wide, and the upper mandible is hooked at the tip. These birds have short, rounded wings, and a long, broad, square-ended tail. Their legs and feet are small and weak, and are used only for perching. The toe arrangement of trogons is of an unusual and distinctive pattern known as heterodactylous. The first and second digits point backwards, and the third and fourth forwards. This arrangement of the toes occurs in no other group of birds.

Trogons are colorful birds, with bold patterns of bright red, green, blue, yellow, black, or white. There is bare, brightly colored skin around the eye . The tail has two rows of large white spots underneath. The sexes are dimorphic in most species, having differing plumage. Female trogons are beautiful birds, but somewhat less so than the males.

Trogons feed largely on insects and spiders, although species of the Americas also eat large quantities of fruits . Some species also eat snails , small lizards, and frogs . Trogons spend much of their time perched in a stiffly erect stance on mid-canopy branches, making occasional sallies to catch insects or pluck fruits, often using a hovering flight.

Trogons are solitary birds. They defend a breeding territory, which is proclaimed by simple calls. Their nests are located in a cavity excavated in rotten wood in a tree , or dug into a termite nest or paper-wasp nest. Trogons lay two to four pale-colored, unspotted eggs that are incubated by both parents. The nestlings are born naked and almost helpless, and are fed with insects regurgitated by the parents. Both sexes share in the care and feeding of the young.

Species of trogons

Most species of trogons are tropical in their distribution. One species, however, breeds as far north as the United States. This is the coppery-tailed or elegant trogon (Trogon elegans), which breeds in mountain forests of southern Arizona, and south into Central America. One of the best known of the Central American trogons is the resplendent quetzal (Pharomachrus mocino), which ranges from Mexico to Nicaragua. This species is brilliantly colored, with the male having greenish hues on the back, breast, tail, and crested head, a vivid red belly, black around the eyes and wings, and yellow bill and feet. The tail of the resplendent quetzal is extended by 24-inch-long (60 cm) plumes, several times longer than the body. This impressive tail is the origin of an alternative common name, the train-bearer.

The resplendent quetzal was sacred to the Maya and Aztecs, and represented the god Quetzalcoatl. This bird is still a culturally important symbol within its range. Stylized renditions of quetzals are prominent in much of the folk art in Central America, particularly in Guatemala, where it is the national bird. Unfortunately, the quetzal has become extremely rare over much of its range, because of deforestation and hunting.

The red-headed trogon (Harpactes erythrocephalus) is a relatively widespread Asian species, occurring from Nepal and south China through Indochina to Sumatra in Indonesia. The male has a bright red head and breast, a cinnamon back and tail, and black wings, while the female lacks the red head. The Narina trogon (Apaloderma narina) occurs over much of sub-Saharan Africa. The blue-crowned trogon (Trogon curucui) is a widespread species of South American tropical forests, breeding from Columbia to northern Argentina.

The Cuban trogon (Priotelus temnurus) only occurs on that island , while the Hispaniolan trogon (Temnotrogon roseigaster) only occurs on Hispaniola (Haiti and the Dominican Republic). These are both monotypic genera, each containing one species, both of which are rare and endangered, mostly because of habitat loss. Other threatened species include the eared quetzal (Euptilotis neoxenus) of Mexico and the nearby United States, and the Ward's trogon (Harpactes wardi) of Southeast Asia.

Resources

books

Forshaw, Joseph. Encyclopedia of Birds. New York: Academic Press, 1998.

Bill Freedman

KEY TERMS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Dimorphic

—This refers to species in which the sexes differ in size, shape, or coloration.

Heterodactyly

—An arrangement of the toes, in which the first two point backwards, and the third and fourth forwards. This only occurs in the trogons.