White-tailed deer and cattle diets at La Michilia, Durango, Mexico.

Abstract

Fecal analysis was used to determine the relationships between white-tailed deer (Odocoileus virginianus couesi[Coues and Yarrow]) and cattle diets (Beef Master, Hereford and criollo), in Durango, Mexico. Deer preferred shrub and tree species (85% of the diet), whereas cattle preferred grasses (61%). Although diets varied seasonally, as did forage availability and quality, the same selective forage pattern was maintained throughout the year. There was a significant difference in the use of different plant groups between the 2 herbivores. The diet overlap index (50.51%) suggested competition during the wet season, but forage was abundant (628 kg/ha dry weight biomass compared with 380 kg/ha in the dry season), thus reducing potential conflicts. Deer and cattle can simultaneously forage in this ares without detriment to either species. The vegetation can maintain a stable composition under higher utilization levels when used by 2 herbivores with different forage patterns than when used by only 1 herbivore.