The
Greater Prairie Chicken, Tympanuchus cupido, is a large bird in
the grouse family. This North American species was once abundant,
but has become extremely rare or extinct over much of its range
due to habitat loss. There are current efforts to help this species
gain the numbers that it once had. One of the most famous aspects
of these creatures is the mating ritual called booming.
Description
Adults of both sexes are 19 inches (480 mm) long, medium sized,
stocky, and round-winged. Their tails are short, round, and dark.
Adult males have a yellow-orange comb over their eyes. Males also
have dark, elongated head feathers that can be raised or lain along
neck. A circular, orange unfeathered neck patch can be inflated
while displaying. Adult females have shorter head feathers and lack
the male's yellow comb and orange neck patch.
Subspecies
There are three subspecies;
- The
Heath Hen, Tympanuchus cupido cupido, which was historically
found along the Atlantic coast is extinct. It was possibly a
distinct species; in this case the two other forms would be
T. pinnatus pinnatus and T. p. attwateri.
- Attwater's
Prairie Chicken, T. c. attwateri is endangered and restricted
to coastal Texas.
- The
Greater Prairie Chicken, T. c. pinnatus, is now restricted to
a small section of its former range.
Population
and habitat
Greater Prairie Chickens prefer undisturbed prairie and were originally
found in tall grass prairies. They can tolerate agricultural land
mixed with prairie, but the more agricultural land the fewer Prairie
Chickens. Their diet consists primarily of seeds and fruit but during
the summer they also eat insects and green plants. These birds were
once widespread all across the oak savanna and tall grass prairie
ecosystem. The Greater Prairie Chicken was almost extinct in the
1930s due to hunting pressure and habitat loss. They now only live
on small parcels of managed prairie land. It is thought that their
current population is about 459,000 individuals. In May 2000, the
Canadian Species at Risk Act listed the Greater Prairie Chicken
as extirpated in its Canadian range (Alberta, Saskatchewan, Manitoba,
Ontario)[1].
Threats
Greater Prairie Chickens are not threatened by severe winter weather.
When the snow is thick they "dive" in to the snow to keep
warm. A greater threat to the Prairie Chickens comes in the from
of spring rains. These sometimes drenching rains can wreak havoc
on their chicks. Another major natural threat is drought. A drought
can destroy food and make it difficult for the chicks.
Human
interactions are by far the greatest threat. The conversion of native
prairie to cropland is very detrimental to these birds. It was found
in a radio telemetry study conducted by Kansas State University
that "most Prairie Chicken hens avoided nesting or rearing
their broods within a quarter-mile of power lines and within a third-mile
of improved roads." (Kansas Department of Wildlife and Parks)
It was also found that the Prairie Chickens avoided communication
towers and rural farms.
Sexual
behavior
Greater Prairie Chickens do not migrate. They are territorial birds
and often defend their booming grounds. These booming grounds are
the area in which they perform their displays in hopes of attracting
females. Their displays consist of inflating air sacs located on
the side of their neck and snapping their tails. These booming grounds
usually have very short or no vegetation. The male Prairie Chickens
stay on this ground displaying for almost two months. The breeding
season usually begins in the United States starting in Late March
throughout April. During this time the males establish booming sites
where they display for the females. The one or two most dominant
males will do about 90% of the mating.
After
mating has taken place, the females will move about one mile from
the booming grounds and begin to build their nests. Hens lay between
5 and 17 eggs per clutch and the eggs take between 23 and 24 days
to hatch. There are between five and 10 young per brood. (INRIN,
2005). The young are raised by the female and fledge in one to four
weeks, are completely independent by the tenth to twelfth week,
and reach sexual maturity by age one (Ammann, 1957). One problem
facing Prairie Chickens is competition with the Ring-necked Pheasants.
Pheasants will lay their eggs in Prairie Chicken nests. The pheasant
eggs hatch first; this causes the Prairie Chickens to leave the
nest thinking that the young have hatched. In reality the eggs did
not hatch and the young usually die because the mother is not there
to incubate the eggs.
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