Threatened and Endangered Species - Status Reports
Date Published: March 1998
Number of Pages: 67
Author(s): David W. Hays, Michelle J. Tirhi and Derek W. Stinson
Sharp-tailed grouse have declined throughout North America. Of the six recognized subspecies, the Columbian sharp-tailed grouse is the rarest. The Columbian subspecies historically ranged from southern British Columbia, south along the eastern slope of the Cascade and Sierra Nevada mountain ranges to northeastern California, and east to Colorado and Utah.
Columbian sharp-tailed grouse numbers have drastically declined in Washington over the past 100 years. Sharptails were plentiful in eastern Washington when early explorers arrived and became important game birds that were harvested in abundance. Increased agriculture from 1850 to 1880 initially provided more food for sharptails, but continued conversion of grassland and sagebrush habitats to agriculture, along with increased settlement after 1900, contributed to sharptail population declines. By the 1920's, sharptails were extirpated from much of their historic range. Harvest levels were reduced after 1920 and the hunting season for sharp-tailed grouse was closed from 1933 to 1953. The population continued to decline after 1950, due to intensive livestock grazing on remnant patches of shrub/meadow steppe. By the 1950's, sharp-tailed grouse had disappeared from at least six counties where they were once abundant. Sharp-tailed grouse persist in eight scattered subpopulations in Douglas, Lincoln, and Okanogan counties. Areas supporting the most sharptails include Dyer Hill in Douglas County, Swanson Lakes in Lincoln County, and Tunk Valley and Nespelem in Okanogan County.
In 1970, the Department began standardized annual surveys (lek counts) in areas known to contain significant grouse subpopulations. A rough estimate of statewide population size in 1970 was 7,430 birds. The estimated sharp-tailed grouse breeding population in 1997 was 716 birds. Accurate population estimates are difficult to obtain, because all males may not be on leks during counts, lek counts often include some females, not all leks are known, and exact sex ratios are uncertain. The total population may be closer to 1,000 individuals.
A total of 130 different sharp-tailed grouse leks were documented in Washington between 1954 and 1997; only 51 were active in 1997. Birds per lek declined from 16.4 in 1970 to 8.1 in 1997, though this trend may be exaggerated by the increase in the number of smaller leks added to the counts. From 1954 to 1994, 66% of active leks disappeared in Douglas County, 72% disappeared in Okanogan County, and 63% disappeared in Lincoln County. The loss of these active leks is part of a pattern of population decline, range reduction, and isolation of remaining populations. All remaining subpopulations are small and isolated from one another. Four are under immediate threat of extirpation, with less than 25 birds each. Two of the three largest subpopulations left outside of the Colville Indian Reservation are of concern, in part due to their small size (estimated less than 100 individuals each). The Lincoln County population is likely the most stable population outside the Colville Indian Reservation, with substantial ownership by the Washington Department of Fish and Wildlife and the Bureau of Land Management.
The sharp-tailed grouse decline in Washington is primarily attributed to loss and degradation of habitat. Excessive livestock grazing, agriculture, and brush control using herbicides and fire are primarily responsible for loss of habitat. The meadow steppe (fescue/wheatgrass) of the Palouse and the shrub-steppe (sagebrush/bunchgrass) of the Columbia Basin were replaced with cultivated fields. Remaining sharptail habitat is severely fragmented and in poor condition, especially in Okanogan County where winter habitat has been removed. Loss of nesting, brood rearing, and wintering habitat are important factors limiting population growth.
Cooperation is needed among private landowners, public agencies, and Native American tribes on managing habitat to ensure the survival of sharp-tailed grouse. Most of the sharp-tailed grouse remaining in Washington are on either private lands or the Colville Indian Reservation. Listing sharp-tailed grouse may be of concern for private landowners due to fears of government regulation. Some landowners will benefit because lands important to sharp-tailed grouse are given higher priority for enrollment in the USDA Conservation Reserve Program (CRP).
The CRP program is currently the main financial incentive for private landowners to provide sharp-tailed grouse habitat. Lands enrolled in the CRP appear to support the remaining sharp-tailed grouse subpopulations. Washington farmers have a total of about 871,000 ac enrolled, including 483,000 that were re-enrolled in 1997. This included some important sharp-tailed grouse habitat. If CRP lands were placed back into grain production, further declines in the number of sharp-tailed grouse would result.
Sharp-tailed grouse in Washington are at risk because they have been reduced to small isolated populations, some of which are on degraded habitat. Most of the remaining sharptail habitat is on private lands and is threatened by further alteration and fragmentation. Other than the Conservation Reserve Program, there are no cooperative agreements or mechanisms in place to ensure the long-term preservation or restoration of sharptail habitat.
For these reasons, the Department recommends that the sharp-tailed grouse be designated a State Threatened species.
Hays, D. W., M. J. Tirhi, and D. W. Stinson. 1998. Washington state status report for the sharptailed grouse. Wash. Dept. Fish and Wildl., Olympia. 57 pp.
Draft documents are provided for informational purposes only. Drafts may contain factual inaccuracies and may not reflect current WDFW policy.