|
The Columbian sharp-tailed grouse was petitioned for listing
in 1999. A 90-day finding, in 2006, concluded that a listing
was not warranted.
Description and Life History
The Columbian sharp-tailed grouse is one of seven recognized subspecies
of sharp-tailed grouse that have been described in North America. Columbian
sharp-tailed grouse are brownish-gray with many small buff and black markings,
a white belly, and a long, mostly white, wedge-shaped tail. Compared
to the other subspecies, Columbian sharp-tailed grouse are the smallest
and have darker gray plumage, more pronounced spotting on the throat,
and narrower markings on the underside.
Sharp-tailed grouse males display in the spring to attract
females to dancing grounds called leks. Established leks may be
used for many years, although their locations may shift over time. After
breeding, females build nests under shrubs or grasses, incubating
eggs for 21 to 24 days; re-nesting has been documented on several
occasions in sharp-tailed grouse. After hatching, chicks eat mostly
insects and remain with their mothers in broods for 6 to 8 weeks. Their
average life-span is about three years.
Spring-to-fall home range sizes of Columbian sharp-tailed grouse
are relatively small and the areas used are usually within a short
distance of a lek. Columbian sharp-tailed grouse remain in shrub-steppe
habitats until the onset of snow, when they form small flocks and
move to either riparian or mountain shrub communities where vegetation
remains above the snow line. Seasonal movements to wintering areas
from breeding grounds are typically less than three miles.
Habitat
Columbian sharp-tailed grouse rely on a variety of good quality habitats
within sagebrush-bunchgrass, meadow-steppe, mountain shrub, and riparian
zones. Various upland habitats, with a component of denser riparian
or mountain shrub habitat to provide escape cover, are important to the
subspecies from spring to fall. The availability of suitable wintering
habitat, containing a dominant component of deciduous trees and shrubs,
is also thought to be a key element to healthy Columbian sharp-tailed
grouse populations.
Reasons for Decline
Excessive hunting in the mid- to late-19th century is thought to be a
major contributing factor to the early extirpation of local populations
and the initial reduction of the subspecies' range. Since the turn
of the 20th century, the conversion of native habitats to crop production
and habitat degradation as a result of livestock grazing are thought
to be the primary factors in population declines and range reduction
(Buss and Dziedzic 1955; McDonald and Reese 1998). Factors such
as drought, fire, and inclement weather may also significantly affect
the population in Oregon due to the small population size.
Range
Historically, the Columbian sharp-tailed grouse range extended westward
from the continental divide in Montana, Idaho, Wyoming, and Colorado
to northeastern California and eastern Oregon and Washington; southward
to northern Nevada and central Utah; and northward through central
British Columbia. The species was gone from Wallowa county by the
late 1940s, and the last Columbian sharp-tails in Oregon probably
occurred in Baker county, Oregon. Columbian sharp-tailed grouse
were extirpated from Oregon in the 1960s. Columbian sharp-tailed
grouse in Oregon currently only occupy a small portion of available
habitat in Wallowa county outside of Enterprise, Oregon.
Conservation Measures
Most of the habitat areas in Oregon that are currently or
may potentially be used by Columbian sharp-tailed grouse occur on
privately-owned lands. Some large portions of these privately-owned
lands have been withdrawn from crop production and planted to native and
non-native cover under the federal Natural Resources Conservation Service
(NRCS) Conservation Reserve Program (CRP), established in 1985. A
portion of Wallowa county that currently supports a reintroduced population
of Columbian sharp-tailed grouse has been designated a Conservation
Priority Area by the NRCS under the CRP program in order to benefit
the species (Coggins and Matthews 2000).
A total of 317 grouse from southeastern Idaho and northeastern Utah have
been released in Wallowa County, Oregon, since 1991. Grouse moved
from the initial release site at Clear Lake Ridge to the Leap Area
north of Enterprise, Oregon. Therefore, subsequent releases have
been made at the Leap Area. The Leap Area has been used by the sharp-tailed
grouse from 1991 through the present. The grouse have established
leks at the Leap Area and at least two leks have been active for
more than 11 years. Lek counts and summer flush surveys since the
initial release indicate a small, persisting population of grouse
is present in Wallowa county. These counts also indicate fluctuations
in grouse numbers since their reintroduction in 1991. More reintroductions
are planned for spring 2008. (ODFW 2008)
References and Links
Buss, I.O. and E.S. Dziedzic. 1955. Relation of Cultivation to the Disappearance
of the Columbian Sharp-tailed Grouse from Southeastern Washington. Condor.
57:185-187.
Coggins, V. and P. Matthews. 2000. Columbian Sharp-tailed Grouse
Project, Wallowa County. Unpublished Progress Report, January 20,
2000. 3 pp.
McDonald, M.W. and K.P. Reese. 1998. Landscape Changes Within the
Historical Distribution of Columbian Sharp-tailed Grouse in Eastern
Washington: Is There Hope? Northwest Science 72:34-41.
Oregon Department of Fish and Wildlife. 2008. Upland Game Birds
- Re-introducing Columbia sharp-tailed grouse
U.S. Fish and Wildlife Service. 2006. Endangered and Threatened Wildlife
and Plants; 90-day Finding on a Petition to List the Columbian Sharp-tailed
Grouse as Threatened. FR
71(224): 67318-67325.
|