WHITE-TAILED DEER AND CATTLE DIETS AT LAMICHILIA, DURANGO, MEXICO

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 kp!ha in the dry season), thus reducing potential conflicts. Deer and cattle can simultaneously forage in this area 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.