Distribution in the Americas
Eared Quetzal occurs in the Sierra Madre Occidental mountain range and the adjacent Pacific slope, between 1800-3000 m (Howell and Webb 1995). It ranges from northwestern Chihuahua and northeastern Sonora through Durango, Zacatecas, and Nayarit to western Michoacán (Miller et al. 1957, Howell and Webb 1995). It is endemic to Mexico, except for sporadic records from the southwestern United States.
In 1977, Eared Quetzal was first reported in the United States from South Fork Cave Creek, Arizona. Since then, the birds have been seen sporadically but unpredictably in southeastern Arizona and New Mexico, attempting to nest once in 1991, but failing due to a cold storm (Taylor 1994, Johnsgard 2000).
Distribution outside the Americas
Eared Quetzal does not occur outside of the Americas.
Eared Quetzal is a bird of the pine, pine-oak, and pine-evergreen forests of Mexican highlands, ranging between 1800-3000 or 3100 m (Howell and Webb 1995, Parker et al. 1996). Earlier impressions were that the bird lived exclusively in undisturbed forest and many people have associated it with steep river canyons (Russell and Monson 1998, Taylor 1994, Johnsgard 2000).
More recent research has not only changed perceptions on Eared Quetzal’s abundance but has also given more details on their habitat preferences. A survey of the Sierra Madre Occidental highland forests divided these into three: canyon forest (stunted forest on exposed steep slopes with thin soils), dry-open forest (lower elevation, rocky forest), and mesa forest (high altitude plateau or gentle slope forest with large pines and many snags; Lammertink et al. 1996). This study found that in all seasons, Eared Quetzal was most abundant in canyon forest, where surveyors encountered an average of 26.8 individuals for every 100 observation hours (indicating near-daily encounters), which is significantly higher than the 7.9 and 5.2 encounters in the other two habitats. This bias was consistent in undisturbed forests of all three types and not likely due to the significantly higher abundance of undisturbed canyon forests when compared to the mesa forests (Lammertink et al. 1996). In addition to finding quetzals in 33 locations of primary forest, this study also found them in 21 locations of disturbed forests, mostly through incidental sightings. They were not able to compare the abundances of the bird in both habitats because surveys were only done in undisturbed habitat, but they conclude that finding the bird in secondary forest is not unusual (Lammertink et al. 1996). A study comparing the birds of logged and unlogged forests of Chihuahua found the Eared Quetzal more times in the former (12 individuals compared to 5), although this is likely because they suspended surveys in unlogged areas due to safety issues (Miller and Chambers 2007). However, the bird was abundant in both forest types.
Gonzalez-Rojas et al. (2008) conducted a study in the breeding biology of Eared Quetzal in pine-oak forests (genus Pinus and Quercus), fir forests (Pseudotsuga and Abies), and canyon vegetation that included pines and quaking aspens (Populus tremuloides). Pine-oak forests of the quetzal’s range are generally made up of Pinus leiophylla, P. engelmanni, P. durangensis, Quercus arizonica, Q. oblongifolia, Q. grisea, Q. emoryi, and Q. hypoleucoides, whereas pine forests are dominated by Pinus ayacahuite and P. ponderosa (Navarro-Singüenza and Lammertink 2000).
The birds found in Arizona tend to appear in steep, rocky canyons with habitat that is similar to that preferred by birds in Mexico (Taylor 1994, Johnsgard 2000).
Eared Quetzal was first seen in the United States in 1977 and has been sighted sporadically since then. It nested once in 1991 but that nest failed, although some people suspect that the numerous birds first seen in 1977 represent a successful nesting attempt (Taylor 1994, Zimmerman 1978). However, no evidence exists of an established population and no other changes in its range have been reported.
No quetzal fossils have been reported. Most trogon fossils date from the Oligocene and Eocene in France and Germany, far from their current range (Mayr 1999). The earliest specimens are 54 million years old from the lower Eocene in Denmark, and 49 million years old from the mid Eocene in Germany. The earliest known trogon with a heterodactyl foot is Primotrogon wintersteini, from the French Oligocene 33 milllion years ago, which is thought to be sister to all contemporary trogons, structurally similar to them but with a smaller eye and narrower bill (Mayr 2009). The oldest known New World fossils are very recent, from the Pleistocene (around 2.6 million years ago), similar to the Hispaniolan Trogon (Priotelus roseigaster) and the Surucua Trogon (Trogon surucua). Despite the current concentrations of trogon diversity in the Neotropics, more fossil evidence has been found in the Old World, supporting the notion that they may have originated in that part of the world (Espinosa de los Monteros 1998).