About Rhynchopsitta pachyrhyncha (Swainson, 1827)
Species Nomenclature and Size Classification
The thick-billed parrot (Rhynchopsitta pachyrhyncha) is a medium-sized parrot.
Plumage and Bill Coloration
It is primarily bright green, with a large black bill, and red markings on its forecrown, shoulders, and thighs.
Eye Color by Age
Adult thick-billed parrots have amber-colored eyes, while juveniles have brown eyes.
Underwing Markings
Their underwings have a red leading edge, followed by a blackish-green stripe, a yellow stripe, and dark green on the rest of the underwing.
Tail Coloration
The tail is black.
Standard Size and Weight
This species measures 38 cm (15 in) long and weighs between 315–370 g (11.1–13.1 oz).
Captive Lifespan
Thick-billed parrots can live up to 33 years in captivity.
Morphologically Similar Species
It resembles the larger military macaw (Ara militaris), which has a proportionally longer tail, blue flight feathers, and a blue rump, as well as the lilac-crowned amazon (Amazona finschi).
Phylogenetic Relatives Note
Note that these similar species are not the thick-billed parrot's closest phylogenetic relatives, which are discussed in Taxonomy.
Vocalization Characteristics
The thick-billed parrot's voice is high-pitched and similar to a macaw's, made up of various harsh, rolling calls that have been compared to human laughter.
Captive Temperament and Breeding Traits
While the species can become easily hand-tame, it is nervous, difficult to breed in captivity, and has very low reproduction rates.
Captive Mimicry Ability
Captive thick-billed parrots are moderate voice mimics, capable of learning a few words and phrases.
Pet Trade Popularity and Demand
However, their piercing calls and relatively less bright coloration have kept them from being popular in the pet trade, and there is currently little demand for them, whether captive-bred or illegally caught from the wild.
Food Manipulation Behavior
Like other parrots, thick-billed parrots manipulate food by holding it with one foot.
Social Behavior Traits
They are highly social: they may share food stored in their crop (a pouch located in the throat) with other group members, and spend free time preening each other.
Historical Flock Size
Historical records note groups of over 1,000 thick-billed parrots gathering in a single location.
Habitat and Elevation Range
The thick-billed parrot inhabits temperate conifer forests, pine forests, mature pine-oak forests, and fir forests at elevations between 1200 and 3600 meters.
Current Native Range
It is mostly restricted to the Sierra Madre Occidental in the Mexican states of Chihuahua and Durango.
Former United States Range
Its former range included the southwestern United States, specifically Arizona and New Mexico.
Historical Range Extent Notes
Early records also place the species in far west Texas—ornithologist John James Audubon sighted thick-billed parrots in El Paso in 1827—and possibly as far north as Utah.
United States Movement Patterns
Records from Arizona and New Mexico note that the birds visited these areas regularly, and over-wintered in Arizona.
United States Extirpation Drivers
However, heavy shooting, logging, and development coincided with these records and ultimately drove the thick-billed parrot to extirpation in the United States.
Potential Colonial Disruption Impact
European colonization disrupted traditional Native American ways of life, which greatly reduced the range of some bird species that relied on Native American irrigation and farmland; it is possible that the thick-billed parrot was also negatively affected by this change.
Current Extant US Native Parrot Status
After the extinction of the Carolina parakeet (Conuropsis carolinensis) and the extirpation of the thick-billed parrot, the green parakeet (Psittacara holochlorus) is now the only extant native parrot species in the United States.
Last Confirmed US Sightings
The last confirmed sightings of thick-billed parrots in the southwestern United States were in 1935 and 1938 in Arizona's Chiricahua Mountains.
