Location: Rangeland and Pasture ResearchTitle: Using gas chromatography to determine winter diets of sage-grouse in Utah. Author
Submitted to: Journal of Wildlife Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/5/2011
Publication Date: 11/14/2011
Publication URL: http://handle.nal.usda.gov/10113/55210
Citation: Thacker, E.T., Gardner, D.R., Messmer, T.A., Guttery, M., Dahlgren, D.K. 2011. Using gas chromatography to determine winter diets of sage-grouse in Utah. Journal of Wildlife Management. 76(3):588-592. Interpretive Summary: Currently, wildlife managers and researchers do not have a simple solution for determining sage-grouse winter diets. Researchers at both Utah State University and USDA-ARS proposed to use chemical analysis of sage-grouse fecal pellets to determine winter diets. The study consisted of collecting sage-grouse fecal and sagebrush samples from winter flock locations. Pellet and sagebrush samples were analyzed using gas chromatography to create terpene profiles. The analysis showed that gas chromatography could be used to determine sage-grouse winter diets using terpene profiles. Sage-grouse pellet samples contained mostly black sagebrush. Analysis of sage-grouse fecal pellets using gas chromatography is a feasible option for determining winter diet selection.
Technical Abstract: Federal and state agencies have recently intensified efforts to conserve existing sage-grouse (Centrocercus urophasianus) habitat. Sagebrush (Artemisia spp.) constitutes the majority (> 99%) of sage-grouse winter diets. The objective of our research was to determine if chemical analysis of fecal pellets could be used to determine sage-grouse winter diet composition. We collected and analyzed fecal pellets and sagebrush samples from 29 different sage-grouse flocks in northwestern and south central Utah. Using gas chromatography, we were able to determine sagebrush composition of sage-grouse fecal pellets. Pellet samples from northwestern Utah revealed that 72% of samples were composed of black sagebrush, 5% were composed of Wyoming sagebrush (A. tridentata wyomingensis) and 22 % of pellet samples contained both species of sagebrush. In south central Utah, 61% of the pellet samples contained black sagebrush, 33% Wyoming sagebrush and 6% contained both species of sagebrush. Gas chromatography can be used to determine sage-grouse winter diets. Additionally, black sagebrush appears to be an important component in winter diets in northwestern and south central Utah.