They are less red on the thighs and the bill is horn horn-colored with dark gray at the base of the upper mandible. Thick-billed parrots live in the Hidalgo area of New Mexico and the Cochise, Graham, Pima, Pinal, Santa Cruz, and Yavapai counties of Arizona. They prefer mature pine-oak, pine, and fir forests in the altitudes of 1219 to 3658 meters in the mountains. The Chihuahua Pine is the most common species in occupied areas, but a number of pine and oak species are used. Clutches are comprised of two to four eggs.
Females spend up to three to four hours a day on the eggs.
The parents are usually perched within sight of the nesting tree when transferring food. Both parents roost in the nest each evening. The mountains of southeastern Arizona was the only home to the thick-billed parrot in the United States, until miners discovered what easy targets the birds were and how good they tasted. Then loggers cut down the forests. The last wild thick-billed parrot in the United States was spotted in 1938.