Arizona Water and nutrient content of Forage in Sonoran Pronghorn habitat

We examined diets of Sonoran pronghorn, Antilocapra americana sonoriensis, to determine if they could meet their total water requirements with and without selective foraging. Water availability was based on seasonal measures of plant species composition, moisture, and nutrient content at 2 sites within Sonoran pronghorn range in southwestern Arizona from June 1995 to May 1996. We measured vegetation forage availability using the dry-weight-rank and comparative yield methods and preformed water and organic nutrient content of vegetation using standard laboratory procedures. Water and nutrient content of plants varied significantly between the 2 sites and among 5 seasons. Plant species consumed by pronghorn were higher in moisture and selected nutrients than those not used for forage. Daily maximum water intake predicted by diet models ranged from 1.1 to 6.1 liters/animal/day. After subtracting water theoretically required for excretion, respiration, and evaporation (approximately 50%), predicted water intake from forages was not adequate to meet minimum water requirements (1.8-3.4 liters/animal/day) for 14 of 20 simulated diets. Water developments may improve Sonoran pronghorn habitat if water is a limiting factor for the population and water requirements cannot be met by forage consumption.

Water and nutrient content of Forage in Sonoran Pronghorn habitat, Arizona Academic Article