any of about 35 bird species common to warm regions. Trogons, who constitute the family of Trogonidae, have the belly bright red to yellow in contrast with the dark chest and upperparts. In Africa and America, males are iridescent above; those of Asia lack the gloss but have a touch of pink or red on the head, chest, rump, or tail. Among the best-known species of the trogon family are the quetzals (genus Pharomachrus).