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WatchList
Species Account for Gunnison Sage-Grouse (Centrocercus
minimus)
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| Photo: Wendy Shattil/Bob Rozinski |
The Gunnison Sage-Grouse was newly described
as a species separate from the Greater Sage-Grouse. It is
characterized by a smaller body size, unique plumage, and
low genetic variation; differences in mating displays and
vocalizations have also been noted. It is found only in six
or seven counties in Colorado, and one in Utah. The Gunnison
Basin in Colorado comprises over half its entire world range.
The bird’s habitat is shrub-steppe below 9,200 feet
including sagebrush, riparian areas, meadows. The bird uses
different habitats for leks, nesting, brood-rearing, and winter
at various times of the year. Lek habitat is dominated by
low, open vegetation with sagebrush areas within 400 yards
with a canopy cover of at least 20% and a grass canopy cover
of at least 25%.
Nesting takes place within the sagebrush
community and is characterized by sagebrush canopy covers
of up to 40%, grass heights of a minimum of 6 inches and grass
cover of a minimum of 30% with a mixture of 10% forbs. Brood-rearing
habitat is along the edges and into meadows and riparian areas
in areas with a large grass component and a high percentage
of forbs. Winter habitat is determined primarily by snow depth.
Sage-Grouse eat only sage-brush leaves during the winter and
often can only find exposed plants in drainages where vigorous
sagebrush growth occurs during the spring and on southern
or westernly aspects on slopes of greater than 5%. Other areas
used during the winter include wind-swept mesas and ridge
tops. For the grouse, winter habitat as well as the leks,
nesting area and brood habitats are equally important. Winter
use sites are critical for the species and may change within
and between years depending upon climatic conditions. Lek
sites are traditional areas that may have been used for thousands
of years.
The total estimated population size is
less than 4,000 breeding birds, with over half existing in
the Gunnison Basin. At present the population of the Gunnison
Sage-Grouse is declining in Colorado (it declined 11% in 1999
in the Gunnison Basin) and its distribution has been reduced
substantially from historical levels. The pressing threats
to the Gunnison Sage-Grouse continue to be the loss, degradation,
and fragmentation of habitat. Some private landowners on lands
where leks are located have put conservation easements on
their property. The local, state, and federal agencies are
actively trying to work to increase grouse numbers and those
agencies are currently very aware of their importance to Sage-Grouse
conservation.
Critical to the populations’ recovery
is keeping specific breeding areas confidential. The use of
ATVs is a threat to the bird. Concern about the species' conservation
status prompted the Colorado Division of Wildlife and the
Bureau of Land Management to take the lead in organizing a
citizen-based group, the Gunnison Sage-Grouse Working Group,
with all stakeholders present to develop a Conservation Plan
for the bird in the Gunnison Basin. The plan was completed
in 1997 and is being implemented. As stated in the plan, the
overall goal is “to manage the Gunnison Basin watershed
in a manner that restores Gunnison Sage-Grouse distribution
and numbers as determined by the carrying capacity of the
habitat.” The plan addresses such threats as decline
in habitat quality, habitat loss and fragmentation, and physical
disturbance to bird populations. Actions suggested by the
plan include lek enhancement, riparian area restoration, nest
habitat treatments, improved livestock management, developing
Best Management Practices, and nest predator research.
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