Accepted Manuscripts / Nesting Ecology of Greater Sage Grouse at the ...
Nesting Ecology of Greater Sage Grouse at the Eastern Edge of their Historic Distribution
Katie M. Herman-Brunson, Kent C. Jensen, Nicholas W. Kaczor, Christopher C. Swanson & Mark A. Rumble
Greater sage‑grouse (Centrocercus urophasianus) populations in North Dakota declined approximately 67% between 1965 and 2003 and are listed as a Priority Level 1 Species of Special Concern by the North Dakota Game and Fish Department. The habitat and ecology of this species at the eastern edge of its historical range is largely unknown. We investigated nest site selection by greater sage‑grouse and nest survival in North Dakota during 2005 and 2006. Sage‑grouse selected nest sites in sagebrush (Artemisia spp.) with more total vegetative cover, greater sagebrush density, and greater 1-m visual obstruction from the nest than random sites. Height of grass and shrub (sagebrush) at nest sites were shorter than random sites because areas where sagebrush was common were sites in low seral condition or dense clay or clay-pan soils with low productivity. Constant survival estimates of incubated nests were 33% in 2005 and 30% in 2006. Variables that described the resource selection function for nests were not those that modeled nest survival. Nest survival was positively influenced by percent shrub (sagebrush) cover and grass height. Daily nest survival decreased substantially when percent shrub cover declined below about 9% and when grass heights were less than about 16 cm. Daily nest survival rates decreased with increased daily precipitation.