The Greater Sage-Grouse has been listed as a Candidate Species for consideration by the Endangered Species Act.
Greater Sage-Grouse (Centrocercus urophasianus; hereafter sage-grouse) are a sagebrush obligate species, native to the sagebrush steppe of western North America. They nest in shrub steppe habitats from the western edge of the Great Basin eastward into the Dakotas and Nebraska. Sage-grouse populations are declining throughout their range and have been in decline in Mono County, CA as early as 1916. This decline is attributed in part to anthropogenic encroachment and habitat loss.
The role of USGS is to conduct a series of studies that evaluate habitat at multiple scales. We are estimating vital rates of sage-grouse at different life stages to assess how environmental factors, including vegetation and anthropogenic effects, at varying scales affects survival. USGS collects data using sound scientific methodology, in conjunction with contemporary statistical analysis and complex mathematical modeling, to best inform management decisions in protecting this species of conservation concern.
Our current projects examine patterns in habitat selection, which is the disproportionate use to availability of resources or conditions by organisms. These patterns are complex and the study of these patterns has become a priority in conserving wildlife species. Organisms are thought to use resources and occupy areas that optimize their fitness (i.e., survival and reproduction). Beneficial management practices are those that preserve and improve environmental factors that are selected by an individual organism for the purpose of increasing survival and reproduction. However, to identify these environmental factors, it is challenging and often necessary to identify links between an organisms’ fitness and their habitat-based decisions.
Our research goals are to link habitat use or selection to grouse fitness, such as relationships between nest success and habitat-related decisions by females. It is generally assumed that selection of habitat attributes is related to an aspect of fitness, but these links had not been quantified for many sage-grouse populations. Recent research has explored associations between habitat attributes and fitness, and these studies have highlighted the need to focus on identifying relationships between environmental attributes that are selected by grouse and their fitness. Furthermore, recent studies have examined grouse at a single spatial scale and analyses at multiple scales are needed.
The following pages detail our sage-grouse research work in the Bi-State area of Mono Lake County, CA and Lyon County, NV, the Virginia Mountain Range in northwest Nevada, and in northeast Nevada, along the northern portion of the Southwest Intertie Project (SWIP) Corridor.
For more information on these projects, please contact:
Peter S. Coates, Ph.D.
USGS Western Ecological Research Center
Dixon Field Station
800 Business Park Dr. Suite D
Dixon, CA 95620-9648
Tel. Work (530) 669-5073
Current Research Projects
USGS Contact For This Project
Greater Sage-Grouse Chicks
Casazza, M.L., C. T. Overton, M. A. Farinha, A. Torregrosa, J. P. Fleskes, M. R. Miller, J. S. Sedinger, and E. Kolada. 2009. Ecology of greater sage-grouse in the Bi-State Planning Area - Final report, September 2007. U.S. Geological Survey Open-File Report 2009-1113, 50 p.
Casazza, M. L., P. S. Coates, and C. T. Overton. 2011. Linking habitat selection and brood success in Greater Sage-Grouse. Pp. 151-167 in B. K. Sandercock, K. Martin, and G. Segelbacher (editors). Ecology, conservation, and management of grouse. Studies in Avian Biology (no. 39), University of California Press, Berkeley, CA.
Assal, T.J., Veblen, K.E., Farinha, M.A., Aldridge, C.L., Casazza, M.L., and Pyke, D.A., 2012, Data resources for range-wide assessment of livestock grazing across the sagebrush biome: U.S. Geological Survey Data Series 690. http://pubs.usgs.gov/ds/690/