Mule deer and elk winter diet as an indicator of habitat competition

Abstract

Mule deer (Odocoileus hemionus) populations have gradually declined in recent decades, while elk (Cervus elaphus) have often increased throughout their common ranges. The cause is uncertain and a source of debate. Increasing elk numbers on these ungulate winter ranges may be causing competition for resources. We contrast winter diets of mule deer and elk and relate them to population trends of both species on the Mount Haggin Wildlife Management Area in southwest Montana. Elk increased from an observed number of 172 in 1978 to 700 in 1996 and slightly declined in 1997. Likewise, mule deer increased from 202 in 1978 to 586 in 1989, but declined to 288 between 1990 and 1997. The same five browse species comprised 95 percent and 52 percent of the mule deer and elk winter diets, respectively. These data indicate there is a potential for forage competition between mule deer and elk sharing winter ranges. Because elk have a more varied diet (55 percent browse, 32 percent grass, 12 percent forbs) than mule deer (98 percent browse, 2 percent grass, 0.5 percent forbs) on this winter range, it is likely that mule deer will be the most negatively impacted.

Parent Publication

• Proceedings-Shrublands under fire: disturbance and recovery in a changing world; 2006 June 6-8; Cedar City, UT

Citation

Frisina, Michael R.; Wambolt, Carl L.; Fraas, W. Wyatt; Guenther, Glen. 2008. Mule deer and elk winter diet as an indicator of habitat competition. In: Kitchen, Stanley G.; Pendleton, Rosemary L.; Monaco, Thomas A.; Vernon, Jason, comps. 2008. Proceedings-Shrublands under fire: disturbance and recovery in a changing world; 2006 June 6-8; Cedar City, UT. Proc. RMRS-P-52. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 123-126