Sage Grouse Use of Nest Sites in Southeastern Idaho

Abstract

We investigated nest site selection by sage grouse (Centrocercus urophasianus) in southeastern Idaho from 1987 to 1989. During 3 breeding seasons, 79% of 84 nest sites were found under sagebrush (Artemisia spp.). Nest success averaged 53% for grouse that used sagebrush and 22% for birds that used nonsagebrush nest sites. Total vegetative cover for sagebrush and nonsagebrush nest sites was similar. However, grass height was shorter (P = 0.01) at sagebrush compared to nonsagebrush nest sites. Herbaceous cover was important to nesting sage grouse but the relatively low nest success of nonsagebrush nest sites indicated they might provide less than optimal nesting habitat. J. WILDL. MANAGE. 55(3):521-524 Most studies that have examined sage grouse nest site selection reported that >90% of nests were found under sagebrush (Patterson 1952: 114, Gill 1965, Wallestad and Pyrah 1974, Braun et al. 1977, Gates 1983). Other species of shrubs commonly grow in sagebrush habitats (Tisdale and Hironaka 1981) but are seldom used by nesting sage grouse. Only Hulet et al. (1984) reported a relatively high incidence (34%) of sage grouse use of shrubs other than sagebrush (hereafter called nest shrub species) for nest sites. Unfortunately, Hulet et al. (1984) did not address the relationship of nest shrub species to habitat quality and nesting success. Our purpose is to describe the use of nest shrub species by sage grouse in southeastern Idaho and to test the hypothesis that nesting success for grouse nesting under sagebrush is greater than that of grouse nesting under other plant species. We thank E. F. Cassirer, J. F. Kennedy, R. R. Spahr, C. M. Stinson, and D. W. Stinson for aid in collecting nest data. We also acknowledge the support of the Bureau of Land Management, U.S. Forest Service, and Idaho Department of Fish and Game. This manuscript was improved by reviews provided by J. J. Beecham, C. E. Braun, J. A. Crawford, R. L. Eng, T. P. Hemker, J. W. Hupp, T. E. Remington, and an anonymous referee. This paper is a contribution from Idaho Federal Aid in Wildlife Restoration Project W-160-R and contribution No. 560 of the Idaho Forest, Wildlife, and Range Experiment Station.