Well-known for males' elaborate courtship displays, Greater Sage-Grouse are strongly tied to the sagebrush habitats of western North America. The degradation and outright destruction of sagebrush areas has already greatly reduced the historic range of this big grouse, and continued habitat disturbance could result in this species' listing as a federally threatened or endangered species.
Greater Sage-Grouse is a very large, dark grouse with a long, pointed tail. The adult male has a dark gray back, black throat, white breast, and black belly. In full display, a yellow air sac is inflated from underneath the white breast feathers, the tail is fanned, and feather plumes are erected on the head. The female is smaller than the male, with brown throat and breast, and black belly, lacking the male?s yellow air sac and ornate head plumes.
Distribution and Population Trends
Once widespread over much of western North America, the Greater Sage-Grouse has seen its range contract greatly during the past 200 years. It is now found primarily in eastern Montana, Wyoming, northwestern Colorado, Utah, southern Idaho, Nevada, and northeastern California. There is also an isolated population in central Washington. A number of Audubon Important Bird Areas (IBAs) provide important habitat for this species, including California's Big Valley/Ash Creek IBA and Montana's Red Rock Lakes National Wildlife Refuge IBA.
It is difficult to provide an accurate population number for Greater Sage-Grouse, but a 1998 estimate of 142,000 birds is "clearly lower" than historical population levels. This species' historic range once included parts of 16 states and three provinces, but now encompasses only 11 states and two provinces. In all these remaining states and provinces, Greater Sage-Grouse has experienced a range reduction and/or population decline.
Greater Sage-Grouse have long been the subject of fascination and research because of their elaborate courtship displays. Large numbers of males (averages range from 14 to 70 birds, with peak counts in the hundreds) gather on display grounds (known as leks) to perform a "strutting display" for gathering females. Males fan their pointed tail feathers, erect their head plumes, strut forward, and produce a series of "wing swishes," "air sac plops" and a whistle. If a female is interested in a particular displaying male, she will solicit a copulation from him. On a given lek, most females prefer the same displaying males, meaning that a small number of males receive most of the mating opportunities in that area. As is typical with a lek mating system, male Greater Sage-Grouse do not provide females with any resources after mating, and do not give any type of parental care. Females build a nest on the ground, usually some distance (up to several miles) from the lek site where they mated, and lay an average of six to nine eggs. Young birds are precocial, leaving the nest soon after hatching. They receive some parental care from the female, but are capable of feeding on their own. By two weeks, they are capable of making short flights.
As the name suggests, Greater Sage-Grouse are strongly tied to various sagebrush habitats of western North America. Lek sites for this species tend to occur in less-vegetated areas, but sage-grouse nesting sites and wintering areas are both found in areas dominated by various sagebrush species, especially big sagebrush. The diet of Greater Sage-Grouse throughout the year consists largely of the leaves of a number of species of sagebrush. Grasshoppers, beetles, and ants are important food sources for very young birds, and adult birds do eat some insects during the summer, but by and large, the diet of this species is dominated by sagebrush.
The major threat to Greater Sage-Grouse is the continued degradation and destruction of sagebrush habitats across the West. Agriculture has completely eliminated millions of hectares of native shrub-steppe habitat dominated by sagebrush, while additional millions of hectares of shrub-steppe have been stripped of their sagebrush vegetation. Overgrazing and urban development also contribute to the degradation of shrub-steppe habitat.
Most researchers do not believe that recreational hunting is currently a threat to Greater Sage-Grouse populations. It has been suggested that hunting mortality in this and other game birds simply compensates for natural mortality. However, some Greater Sage-Grouse researchers feel that there is little natural mortality in this species during the fall or winter, thus calling into question the notion that hunting rates of as high as 30% are merely offsetting natural deaths that would occur anyway.
Perhaps because of its status as a game bird, Greater Sage-Grouse has been the focus of some conservation concern during recent years. The Western States Sage and Columbian Sharp-tailed Grouse Technical Committee, under the direction of the Western Association of Fish and Wildlife Agencies, called for the revision of old guidelines for managing sage-grouse populations and their habitats. The species faces growing threats from energy development (oil, gas, and wind), diseases, wildfires, and invasive plants. This resulted in the publication of the document "Guidelines to manage sage grouse and their habitats," which provides management recommendations for local agencies trying to conserve these birds.
In 2010, the U.S. Fish and Wildlife Service found Greater Sage-Grouse warranted protection under the Endangered Species Act, but listing was precluded by higher priority species. Because of its status as a candidate species, federal agencies and the public are encouraged to take proactive landscape level actions.
What Can You Do?
Audubon's Important Bird Area program is a vital tool for the conservation of Greater Sage-Grouse as well as other species. To learn more about the Important Bird Areas program and how you can help, visit http://www.importantbirdareas.org
Volunteers are crucial to the success of programs that monitor the status of populations of Greater Sage-Grouse and other bird species. Audubon's Christmas Bird Count (CBC) is one of the longest-running citizen-science monitoring programs in the world and has helped to follow changes in the numbers and distribution of Greater Sage-Grouse. To learn more about the CBC and how you can participate, visit: http://www.christmasbirdcount.org
U.S. National Wildlife Refuges provide essential habitat for Greater Sage-Grouse, and a great number of other species throughout the U.S. and its territories. Unfortunately, the refuge system is often under-funded during the U.S. government's budgeting process. To learn more about how you can help gain much needed funding for U.S. National Wildlife Refuges, visit: http://policy.audubon.org
Connelly, J.W., M. A. Schroeder, A. R. Sands, and C. E. Braun. 2000. Guidelines to manage sage grouse populations and their habitats. Wildlife Society Bulletin 28 (4): 967-985
Kaufman, Kenn. 1996. Lives of North American Birds. Houghton Mifflin Company, New York.
Schroeder, M. A., J. R. Young, and C. E. Braun. 1999. Sage Grouse (Centrocercus urophasianus). In The Birds of North America, No. 425 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
Sibley, David A. 2000. The Sibley Guide to Birds. Alfred A. Knopf, New York.