Quetzals are strikingly colored birds in the trogon family. They are found in forests, especially in humid highlands, with the five species from the genus Pharomachrus being exclusively Neotropical, while a single species, the eared quetzal, Euptilotis neoxenus, is found in Guatemala, sometimes in Mexico and very locally in the southernmost United States. In the highlands of the states of Sonora, Chihuahua, Sinaloa, Durango, Nayarit, Zacatecas, Jalisco, and Michoacán, the eared quetzal can be found from northwest to west-central Mexico. It is a Mesoamerican indigenous species, but some reports show that it occasionally travels and nests in southeastern Arizona and New Mexico in the United States. June to October is the mating season for eared quetzals. Quetzals are fairly large, slightly bigger than other trogon species. The resplendent quetzal is the national bird of Guatemala because of its vibrant colour and cultural significance to the Maya.

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 and order Passeriformes 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.