Greater sage-grouse (Centrocercus urophasianus) and sharp-tailed grouse (Tympanuchus phasianellus) are native to large portions of the Columbia Basin in central and eastern Washington. The current ranges of both species are dramatically restricted to small portions of their historical distribution in the state (Schroeder et al. 2000). Sage-grouse and sharp-tailed grouse are landscape scale species that depend on extensive areas of suitable habitat to meet their annual requirements. Loss of connectivity within and between these areas can impede their ability to move between patches of suitable habitat with the potential consequences being: (1) fragmentation of populations; (2) reduced genetic heterogeneity; (3) localized extirpation; (4) susceptibility to the effects of climate change; and (5) reduced population viability.
The Washington Wildlife Habitat Connectivity Working Group (WHCWG) was formed to help incorporate wildlife habitat connectivity into revisions of WDFW’s Wildlife Action Plan and WSDOT’s transportation planning. Participants in the WHCWG include a wide range of agencies involved in natural resource management (state, federal, and tribal), non-governmental organizations, and academia. The mission statement of the WHCWG is “Promoting the long-term viability of wildlife populations in Washington State through a science-based, collaborative approach that identifies opportunities and priorities to conserve and restore habitat connectivity.” To accomplish this mission statement the WHCWG is addressing connectivity patterns at three scales: (1) statewide; (2) ecoregional; and (3) local.
The WHCWG Statewide Analysis was published in 2010 and examined connectivity at the statewide scale for a suite of 16 focal species. Greater sage-grouse and sharp-tailed grouse were two of the focal species included in this analysis. They were selected to represent the Semi-desert vegetation class in eastern Washington based on their use of expansive landscapes, and their sensitivity to alterations in the permeability of landscapes to movement. The statewide scale was addressed in 2010 and the ecoregional scale is currently being addressed for the Columbia Plateau.
- Habitat concentration areas for greater sage-grouse and sharp-tailed grouse tend to be situated at relatively high elevations, away from developed areas and high traffic-volume roads
- Habitats with high permeability (low resistance to movement) are relatively unfragmented, forming a loose configuration of native shrubsteppe.
- Cost-weighted distance and linkage maps show movement between habitat concentration areas in Washington for grouse is likely restricted.
- Leslie A. Robb
- Andrew Shirk
All photos unless otherwise indicated are courtesy of Michael A. Schroeder