Evaluation of Forage Preference Indices for White-Tailed Deer

Abstract

We evaluated the use of 2 areas of different size to obtain forage availability estimates for forage preference rankings of white-tailed deer (Odocoileus virginianus) on a 1,190-ha study area in southcentral Oklahoma. Food preferences were based on forage availability data from the entire study area and each deer's specific habitat use area as determined by radio telemetry for 48 hours prior to killing the animal. We found significant (P < 0.05) agreement between preference rankings-using the 2 methods for 8 of 10 deer. Under similar study area conditions, it would not be necesssary to determine each animal's habitat use to develop preference indices. J. WILDL. MANAGE. 53(1):210-213 Diet studies of white-tailed deer often involve shooting free-ranging animals and subsequent examination of rumen contents. Forage preference values are determined based on the extent a forage species occurs in the diet in relation to its availability. However, availability of forage to an animal often is estimated over an arbitrarily designated area much larger than that used by an animal before it is collected. Forage availability estimates may not accurately reflect what was available to the animal because size of the sampled area can affect the proportion of available forage species (Porter and Church 1987). Thus, availability estimates may result in spurious preference inferences. Our objective was to determine if food preference rankings developed from forage availability estimates from known use areas of wild, free-ranging deer were significantly different than food preference rankings developed using an extensive estimate of forage availability (i.e., forage availability over the entire study area). We thank the staff members at the Noble Foundation Wildlife Unit and many volunteers for their assistance. Funding for this research was provided by the Samuel Roberts Noble Foundation. This manuscript is Contribution TA9-530, College of Agricultural Sciences, Texas Tech University.