flocks of up to several hundred thick-billed parrots could be seen
visiting the mountains of Southeastern Arizona and Southwestern New
Mexico. This information was based on observations of these parrots
during the early 1920’s. New observations indicate these birds have been
located only as far north as the Sierra Madre Occidental in Chihuahua
and Sonora with a range extending south to Jalisco and Michoacan. These
birds inhabit the pine oak forests. Flocks have been seen nesting in the
north during the summer months and then heading south in the winter. It
is felt they are going where the pine seed production is higher.
Thick-billed parrots live in large groups. While feeding in smaller
groups during the day, they will flock in the early evenings, roosting
closely together. In the wild they have been seen eating mainly pine
seeds of various species.
Nesting in the wild appears to occur from June until July, with chicks
fledgling from September until late October. Large pine trees and snags
are where these birds nest. Nests produce one to three chicks
(occasionally 4 chicks). Weaning duration is unknown but thick-billed
parrots in captivity have been seen feeding chicks until the next
nesting season. It has been observed that if chicks from the previous
season are left in the exhibit with the adults the pair does not always
The number of thick-billed parrots in the wild is thought to be in the
thousands, but no real long term census has been done. The terrain where
the birds live makes it very difficult to access the numbers. It is
thought that the population has declined somewhat from the original
studies done in 1980 by Lanning and Shiflett and a few week study done
by Noel Snyder in 1991. In 1973 CITES declared the thick-billed parrot
an endangered species and classified them in Appendix I. During nesting
season the researchers believe they are only seeing 1/3 of the
population. They are unsure where the rest of the birds are. One of the
big projects in the future is to satellite track some of the birds.
Currently the telemetry devices are too heavy.
Logging is a way of life in the forests where thick-billed parrots live.
Even though this parrot is protected in its habitat, it is difficult to
enforce the laws in these remote areas. Numerous logging projects and
forestry practices in Mexico have lead to the reduction in trees and
snags as well as adding to the fire hazard (Enkerlin, 2001). Adequate
forest reserves need to be established and the initiation of a forest
management policy needs to be in place. This would preserve the mature
pine trees and snags which are needed to provide the nesting sites
essential to this species (Lanning and Shiflett, 1980).
In 2000 all the hard work of Dr. Enkerlin and his team was realized in
the formation of the Tutuaca Forestry Reserve at Cebadilla. This is one
of the best thick-billed parrot nesting sites. The agreement gives a 15
year moratorium on the cutting of timber in this important area. There
is great hope that the other nesting areas can also be protected in this
manner. If all the prime breeding areas can be protected this could
allow the birds to get reestablished in greater numbers. Some day they
might fly back on their own into the Chiricahua Mountains.
Never popular as pets, the thick-billed parrots are a psittacine whose
past decline in the wild has not been influenced to a great degree by
the pet trade. Regarded as a rarity in aviculture, new interest in this
species has made it more in demand by private collectors, resulting in
increased international traffic. The extent of the traffic is unknown,
however a large confiscation in the 1980's by the U.S. Fish and Wildlife
Service was an indication of increased illegal trade, an obvious threat
to further depleting wild stocks of these birds. Currently the birds
appear to be going into trade outside North America.
Thick-billed parrots were probably unknown in aviculture until 1918 when
a single bird was held by the National Zoo in Washington D.C. Dealers
found specimens difficult to sell and the birds proved to be unpopular
with aviculturists and pet owners probably due to their loud calls,
powerful bill and destructive habits. In 1959 the San Diego Zoo
possessed the only pair known to exist in captive population in the
United States. By 1963 several pairs were being kept in California and
Arizona. Breeding success of the thick-billed parrot was made in 1965 at
the San Diego Zoo and the Los Angeles Zoo (International Zoo Yearbook).
Since 1963 there have been 458 chicks hatched in the US Facilities
(Thick-billed Parrot Studbook, 2003).
Before the formation of a studbook (1985, SSP 1988) only 9 pairs of
thick-billed parrots had had young prior to 1985. Very few institutions
had these birds and most often were not set up for breeding. Interest in
these birds was lacking, but with the establishment of the studbook zoos
wanted to work with them. The first studbook was published in 1988. At
that time there were only 68 thick-billed parrots registered with 11
facilities participating. In the 2007 studbook there are now a total of
120 birds held in 23 facilities. All of these facilities are dedicated
to breeding this species to reinforce the captive breeding population.
The thick-billed parrot was one of only two parrot species known to be
native to North Arizona and New Mexico on a seasonal basis.
Unfortunately the birds had vanished by the 1920's, probably victims of
hunting pressure and habitat destruction. Foraging primarily upon the
seeds of various pine species, their population may have been affected
by extensive lumber harvests within the region as well as the knowledge
that the lumberjacks were killing them with great frequency for sport
and to eat (Snyder, 1989).
1986 the Arizona Game and Fish Department started a release program in
the Chiricahua Mountains of Arizona. This was part of the historical
range of the thick-billed parrot. The United States Forest Service
manages the mountain areas where a majority of wildlife lives. The
protection of this area has allowed the vegetation to re-establish
itself. When a few larger groups of thick-billed parrots were
confiscated, Dr. Noel Snyder was contacted about starting a release
program for this species. The last birds were released in 1993 after
which it was decided to suspend the program, and work on the
translocation of birds within Mexico.
Although, there has been a great deal of publicity over the past
re-release program, the conclusions as to the “success” of that release
are mixed at best. There were inherent problems with the basic
methodology of the release such as the time of year used, predator
migration patterns and proper parrot acclimation. What can be learned
from that program is how it can be improved upon. The immediate goal,
before taking on another re-release project, is to understand the wild
population, preserve Mexican habitat and to continue to breed and
research the captive population.
The mission of the Thick-billed Parrot SSP is to ensure the survival of
the thick-billed parrot within its historic range. The SSP maintains a
viable captive population, educates the public regarding the
conservation of this native endangered species, and acts to protect and
bolster wild and captive populations by supporting in situ and ex situ
research and conservation projects. The captive population serves as a
refugium for future options, a resource for increasing our knowledge of
thick- billed parrot biology, and as ambassadors for our education
programs. Education programs will be conducted in the United States and
Mexico to foster a strong conservation ethic. We will work to bolster
wild thick-billed parrot populations as well as protect native habitat.
The Thick-billed Parrot SSP proposes to address these issues through the
continuations of the following Action Plan: 1. Support vital field work
and protection of the old growth forests of the Sierra Madre Occidental.
2. Promote communication between zoo programs, field workers, and
government agencies. 3. Using information from field studies, manage
captive flocks to maintain natural flocking, foraging, reproductive, and
predator avoidance behaviors. 4. Identify and support worthy education
programs which further the goals of the SSP. 5. Establish baseline
medical and nutritional information for captive and free-living