Population and Habitat Ecology of Deer on Devils Tower National Monument

Abstract

White-tailed (Odocoileus virginianus) and mule deer (0. hemionus) currently use Devils Tower National Monument and adjacent private agricultural lands year round or migrate from the Monument to other areas. In 1989, a game fence was constructed on the west and north borders of the Monument. Enclosure of the Monument by additional fencing could alter habitat use of deer substantially and create many of the problems associated with island reserves. National Park Service management policy directs the Monument to predict changes in the natural resources under its stewardship. Current deer use of the Monument is not well documented so that a baseline for monitoring long term changes is lacking. The Department of Zoology and Physiology at the University of Wyoming and the Wyoming Cooperative Fish and Wildlife Research Unit, in cooperation with the Devils Tower National Monument, initiated a study in June 1990 to document current population numbers and habitat ecology of white-tailed and mule deer on the Monument. Objectives of this study are to: (1) Evaluate methods to estimate seasonal deer densities on the Monument. (2) Determine seasonal movement patterns and time spent on and off the Monument by radio­collared deer. (3) Determine deer habitat selection patterns of deer on the Monument. (4) Estimate the nutritional carrying capacity of the Monument for deer. Preliminary data on population estimates, movement patterns, and habitat use patterns of deer using the Monument during 1990-1991 were presented in the 1991 Annual Progress Report. This report presents additional data on the population numbers for the period April 1992 to October 1992 and describes vegetation data collected but not yet analyzed.