Species & Ecosystem Science

Shrubsteppe Ecology

	Big sagebrush-bunchgrass community, Horse Heaven Hills near Prosser.
	Sage sparrows are one of several sagebrush-obligate birds in Washington.
	Current (bottom) and historic (top) extents of shrubtsteppe/steppe habitats in eastern Washington. Green=forest; darkbrown=shrubsteppe/steppe; tan=cropland.
	Sagebrush-steppe and rimrock along the Columbia River near Vantage.
	Wheat fields now dominate the historic grasslands of the Palouse Prairie in southeast Washington.

Shrubsteppe communities form the iconic, western landscape of open sagebrush plains, rimrock, and tumbleweeds. Described as vegetation communities consisting of one or more layers of perennial grass with a discontinuous overstory layer of shrubs, shrubsteppe historically dominated the landscape in eastern Washington. Some of the many species of wildlife that inhabit shrubsteppe can only be found in these semi-arid communities. Greater sage-grouse, sage sparrows, sage thrashers, and pygmy rabbits are among an elite group of species that depend on sagebrush and are termed “sagebrush obligates”. A host of other birds, mammals, reptiles, and insects are found primarily in sagebrush-steppe or other shrubsteppe communities.

Today, less than 50% of Washington’s historic shrubsteppe remains (Fig. 1), and much of it is degraded, fragmented, and/or isolated from other similar habitats. Conversion to cropland has resulted in the greatest loss of shrubsteppe in Washington, leading to a fragmented landscape and a differentially high loss of deep-soil communities. Across the Intermountain West, shrubsteppe communities have been lost or degraded by conversion to cropland, extensive energy extraction, and alteration of the vegetation through over-grazing, invasion by exotic plants and changes in fire frequency.

Anthropogenic changes in these unique habitats have caused severe declines in species like the greater sage-grouse and have led to the extirpation of the pygmy rabbit in Washington. Other shrubsteppe-associated species that are likely on the decline include the Washington ground squirrel, Brewer’s sparrow, and burrowing owl. Conversion of shrubsteppe to cropland and other uses is responsible for much of the observed declines in native species; however, the pattern of habitat loss and how remaining habitat is configured on the landscape likely plays a significant role in determining use by wildlife.

Since the 1980s, WDFW scientists have been studying how changes in the landscape in eastern Washington affect shrubsteppe-associated wildlife. Our research has focused on providing information that can be used by land managers to minimize effects of development on shrubsteppe-associated wildlife.

Projects

• Occupancy Modeling of Washington Ground Squirrels Populations
• Effects of land use change on avian communities
• Population Ecology of Greater Sage-Grouse
• Use of Conservation reserve Program lands by Wildlife
• Effects of windpower projects on shrubsteppe birds

Publications

• Changes in the distribution and abundance of Columbian sharp-tailed grouse in Washington
• Changes in the distribution and abundance of sage grouse in Washington
• Conservation assessment of greater sage-grouse and sagebrush habitats
• Distribution of sage-grouse in North America
• Fidelity of sage-grouse to breeding areas in a fragmented landscape
• Fragmentation by agriculture influences reproductive success of birds in a shrubsteppe landscape
• Guidelines to manage sage grouse populations and their habitats
• Historical and current approaches to monitoring to monitoring greater sage-grouse
• Male incubation and multiple brooding in Sagebrush Brewer’s Sparrows
• A meta-analysis of greater sage-grouse Centrocercus urophasianus nesting and brood-rearing habitats
• Parasitism by Brown-headed Cowbirds in the shrubsteppe of eastern Washington
• Predation and the management of prairie grouse
• Predation on real and artificial nests in shrubsteppe landscapes fragmented by agriculture
• Shrubsteppe bird response to habitat and landscape variables in eastern Washington, USA
• Shrubsteppe mapping of eastern Washington using Landsat satellite thematic mapper data
• Status of Washington's Shrub-Steppe Ecosystem: Extent, ownership, and wildlife/vegetation relationships
• Teetering on the edge or too late? Conservation and research issues for avifauna of sagebrush habitats
• Unusually high reproductive effort by sage grouse in a fragmented habitat in north-central Washington
• Use of Conservation Reserve Program fields by greater sage-grouse and other shrubsteppe-associated wildlife in Washington state
• Stiver, S., T. Apa, J. Bohne, D. Bunnell, P. Deibert, S. Gardner, M. Hilliard, C. McCarthy, M. A. Schroeder. 2007. Greater sage-grouse comprehensive conservation strategy. Western Association of Fish and Wildlife Agencies. Cheyenne, Wyoming.
• Schroeder, M. A. 2005. Sharp-tailed grouse. Pages 70-71 in T. R. Wahl, B. Tweit, and S. G. Mlodinow, editors. Birds of Washington. Oregon State University Press, Corvallis, Oregon.
• Schroeder, M. A. 2005. Greater sage-grouse. Pages 67-68 in T. R. Wahl, B. Tweit, and S. G. Mlodinow, editors. Birds of Washington. Oregon State University Press, Corvallis, Oregon.
• Vander Haegen, W. M. 2005. Sage Sparrow (Amphispiza belli). Pages 328-329 in T. R. Wahl, B. Tweit, and S. G. Mlodinow, editors.The Birds of Washington. Oregon State University Press, Corvallis.
• Vander Haegen, W. M. 2005. Sage Thrasher (Oreoscoptes montanus). Pages 299-300 in T. R. Wahl, B. Tweit, and S. G. Mlodinow, editors.The Birds of Washington. Oregon State University Press, Corvallis.
• Connelly, J. W., K. P. Reese, and M. A. Schroeder. 2003. Monitoring of greater sage-grouse habitats and populations. Contribution No. 979, College of Natural Resources Experiment Station, University of Idaho, Moscow, Idaho.
• Vander Haegen, W. M., S. M. McCorquodale, C. R. Peterson, G. A. Green, and E. Yensen. 2001. Wildlife communities of eastside shrubland and grassland habitats. Pages 292-316 in D. H. Johnson and T. A. O'Neil, Managing Directors, Wildlife-habitat relationships in Oregon and Washington. University of Oregon Press, Corvallis, Oregon. 736pp.
• Schroeder, M. A., J. R. Young, and C. E. Braun. 1999. Sage grouse. In The birds of North America, No. 425 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA. 28pp.