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Trogonidae - Trogoniformes

Kingdom: Animalia     Phylum: Chordata     Class: Aves (Birds)     Order: Trogoniformes     Family: Trogonidae

Trogonidae or Trogons, have traditionally been placed near the toucans, parrots, cuckoos, rollers, and jacamars. The closest living relative, the Mousebird, supports molecular evidence that Africa is the trogonsí ancestral home, despite only three of 37 trogon species being found there today. The oldest Trogoniform fossils, found in Europe, date to the Tertiary period, and it is thought that the other surviving groups split from their African relatives between 20-36 million years ago. Divisions within the trogons remain somewhat unclear. One system, which seems more intuitive, proposes three subfamilies based on geography (African, Asian, and American trogons) and eight genera.

Trogons are brightly colored, compact birds with short, rounded wings, broad squared tails, and small legs and feet. Bills are short, stout, and decurved, with serrated tomia (cutting edges) and a wide gape that allows trogons to grasp and swallow prey that is large, squirming, or both. Trogon feet are notable not only in their small size and relative weakness-the birds are unable to rotate on a perch without using their wings-but for their morphology. On each foot, two toes point forward and two point back, but unlike other zygodactyls, trogons have their first and second toes, rather than the first and fourth, directed backwards. This distinctive adaptation may help trogons cling to the sides of trees like woodpeckers, which have a similar toe arrangement.

Adult male trogons are among the most brilliantly colored of all tropical birds. Their notably soft, dense plumage is a brilliant green, blue, or violet on the upper body and chest, with yellow, orange, pink, or red underparts providing kaleidoscopic contrast. Many trogons have distinctive barred or vermiculated wing panels, colored white on black in males and buff on black in females. Females are plainer, with browns and grays replacing the greens and blues of males. Female underparts, however, are often as brightly colored as those of males. Juveniles are mottled brown with white and buff spotting.

Generally sedate, trogons spend most of their time perched immobile and silent. This may be in part an anti-predator strategy balancing the birdsí bright coloration. The main activity periods in early morning and late afternoon are punctuated with short undulatory flights after food or in defense of small territories. There is little evidence of migratory behavior among trogons, although some montane species have been noted to move to lower elevations during the summer non-breeding season to follow fruiting events. Trogons are most often found alone or in pairs. Details of visual displays and territoriality are sparse. Trogonsí calls are typically melodious, loud, and simple. Males may repeat a monosyllabic, plaintive hoot over 100 times and give a hoarse chatter when disturbed. Songs appear to be used in territoriality and possibly mating bonding.

Fruits and insects are trogonsí two main foods, although diets vary. Species in Asia and the New World eat both types of food. The larger species tend to eat a higher proportion of fruit. In Asia and the Americas, trogons often join mixed-species feeding flocks, and rarely follow monkey troops or army ant columns to capture disturbed insects. Smooth-skinned caterpillars are a trogon favorite, but hairy ones are also taken infrequently, along with adult butterflies and moths. The ingestion of noxious insects may account for the unpleasant smell reported for trogon excrement and flesh. Stick insects, beetles, and other large, slow insects are also on the menu, as are the occasional small lizard, snail, or frog. Trogons eat enough fruits to be important seed dispersers. Insects and fruits are obtained on the wing using a technique known alternately as "hawking", for insects, or "hover-gleaning". Trogonsí deeply slotted wings allow them to stall momentarily, without losing flight control, to pluck a food item from the air or protruding stem.

Trogons pair monogamously, probably for life. Among tropical species, breeding occurs around the dry season when food items are more abundant. Spring and summer breeding is typical among species in temperate and arid areas. Pair formation, pair-maintenance, and copulatory behavior are little understood. All trogons are cavity nesters. Mating generally begins with a male finding a suitable nesting spot, beginning excavation, and then advertising for a mate by singing. Both members of the pair help with the construction, which may take several months. Nests are most often built in decaying tree trunks, but epiphyte root masses and occupied termitaries are also used. Excavation is done mostly with the bill, and the nest cavities are either enclosed chambers accessed by an ascending tunnel, or shallow depressions that leave most of the occupying bird exposed. Two to four eggs are laid in the unlined nest cavities. The eggs range from white to greenish or bluish in quetzals. Incubation is 16-21 days and is shared by both sexes, with the female typically taking the night shift. Chicks are fed and brooded by both parents. They are fed mostly on insects, either whole or regurgitated, and must cope with a lack of nest sanitation so pronounced that it may help discourage predators.

Trogons are considered relatively common, although they are sensitive to habitat destruction, in part because of their choosiness when it comes to selecting nesting trees. Trogon numbers have declined near human settlements. Ten trogons were recognized as Lower Risk: Near Threatened on the IUCN Red List in 2002: Diardís trogon (Harpactes diardii), Whiteheadís trogon (H. whiteheadi), Wardís trogon (H. wardi), Bairdís trogon (T. bairdii), the Hispaniolan trogon (Temnotrogon roseigaster), the Eared trogon (Euptilotis neoxenus), the Scarlet-rumped trogon (H. duvaucelii), the Cinnamon-rumped trogon (H. orrhophaeus), the Red-naped trogon (H. kasumba), and the Resplendent quetzal (P. mocinno).

Red-headed Trogon  (Harpactes erythrocephalus) - widespread resident
Malabar Trogon  (Harpactes fasciatus) - widespread resident
Ward's Trogon  (Harpactes wardi) - local resident

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