The high-elevation conifer forests of central Mexico may not seem like typical habitat for parrots, but the Thick-billed Parrot has adapted quite nicely to these northern-type forests. Until the early 20th century, its range extended as far north as Arizona and New Mexico; along with the extinct Carolina Parakeet (
Conuropsis carolinensis), the Thick-billed Parrot is one of only two parrot species whose natural range once included the United States.
The Thick-billed Parrot is a bright green, pigeon-sized bird with a dark, heavy bill. At about 15 inches in length, it is distinguished from similar species by its red forehead and yellow eyering, as well as by smaller red markings on the "shoulders" and "thighs". In flight, both its bright yellow covert stripes and the red of the "shoulder" are conspicuous against the otherwise dark underwing. Its long, pointed wings measure about 32 inches when outstretched. The juvenile has duller red markings, and its large bill is flesh-colored, turning black by the end of the first year. This species is usually found in noisy flocks, the calls of which resemble human laughter. Flocks can be heard from distances of up to two miles, which, sadly, makes them an easy target for poachers.
The high mountains of the Sierra Madre Occidental from Chihuahua and Sonora south to northwest Durango are now home to this parrot. Thick-billed Parrots currently breed within approximately 100 km of the Mexico/Arizona border. Naturally occurring populations have been extirpated from the United States since 1920s. Within its current breeding range, it tends to occur in small, disparate groups within remaining pockets of suitable habitat. This species is a short-distance migrant. Almost all individuals leave the breeding range to winter south of Durango to Colima and Michoacan, Mexico.
This species is a resident of mature, mixed woodlands – especially of pine forests above 1,200 meters. While it has adapted to some partially logged areas, it prefers elevated old-growth areas where it can forage by day and roost on cliffs at night. Breeding is not known to occur below 2300 m.
These high-elevation parrots are pine specialists, dependent upon large stands of pine, spruce and fir for both food and nesting. They mainly eat pinecone seeds, but also acorns, fruits, and other seeds found within their range. Flocks of Thick-billeds are known to wander up to 25 km from nest and roost sites in search of suitable foraging spots. While feeding, a sentinel is usually posted to scan the skies for raptors while the flock feeds. Flocks are usually very systematic when working a small group of pine trees, leaving very little behind. Individuals are similarly thorough when stripping a cone of seeds; methodically consuming an entire cone can take a bird up to twenty minutes.
Breeding occurs in mid-summer to mid-fall, when food is most abundant. Once a pair is formed, the birds will begin to investigate potential nest cavities in old pine trees. Thick-billeds usually modify old woodpecker nest cavities, which they often enlarge by entering the hole and chewing at the insides. One clutch of 2-3 unmarked, cream-colored eggs is laid, then incubated for about 26 days. Only the female incubates the eggs, while the male brings her food. Newly hatched chicks are unfeathered for the first two weeks, but for a sparse layer of down. The female broods her chicks almost constantly for the first three weeks, after which point she begins to leave them unattended while foraging with the male. Young birds fledge after about 60-65 days, by which time they are fully feathered and quite noisy. Fledged young join adult birds in flocks, but remain at least partially dependant upon their parents for many months.
Some populations of Thick-billed Parrots migrate following the breeding season. Seasonal movements have been poorly studied. Our understanding of migration in this species is further complicated by the fact that non-migratory Thick-billed populations are known to wander great distances in search of suitable food sources. It is often difficult to determine the nature of seasonal shifts within a given flocks' range. Populations further south are less likely to move as far after the breeding season concludes.
Lurie, A. and Snyder, N.
Thick-billed Parrots, Field Observations and History. PsittaScene Vol. 13 No.1 February 2001.
Snyder, N.F.R.; Enkerlin-Hoeflich, E.C. and Cruz-Nieto, M.A. 1999. Thick-billed Parrot (
Rhynchopsitta pachyrhyncha).
The Birds of North America, No. 406 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D. C.
Stattersfield, A.J., and D.R. Capper (Eds). 2000.
Threatened Birds of the World. Lynx Editions and BirdLife International, Barcelona and Cambridge.
Noel F. R. Snyder, Susan E. Koenig, James Koschmann, Helen A. Snyder, Terry B. Johnson. Thick-Billed Parrot Releases in Arizona. The Condor, Vol. 96, No. 4 (Nov., 1994), pp. 845-862.
