Spatial and temporal interactions of elk, mule deer, and cattle.

Abstract

Elk (Cervus elaphus), mule deer (Odocoileus hemionus) and cattle share millions of acres of public and private forests and rangelands across the western United States and Canada. These three species have important social, ecological and economic values. Understanding their interspecific interactions may clarify two recurring issues in their management: competition for food and competition for space, both may result in decreased animal fitness. Animal unit equivalents (AUEs) among these three species have been based on equivalent body mass (Society for Range Management 1989), whereby one cow is equivalent to two and one-half elk or to six mule deer. Hobbs and Carpenter (1986) argue that AUEs should be based on dietary overlap, and the argument can be extended to include spatial overlap. Consequently, the ecological impact of one species on the landscape may not be equivalent to another species. Furthermore, allocating forage becomes challenging if managers do not clearly understand the spatial and dietary overlap among these three species. Accurate predictions of ungulate distributions over time and space may help managers regulate densities and understand effects of specific ungulates on ecosystem processes.

Citation

Coe, Priscilla K.; Johnson, Bruce K.; Stewart, Kelley M.; Kie, John G. 2004. Spatial and temporal interactions of elk, mule deer, and cattle. In: Transactions of the 69th North American Wildlife and Natural Resources Conference: 656-669