Sonoran pronghorn use of habitat in southwest Arizona

Abstract

From April 1988 to August 1988 and from March 1989 to August 1989 I studied habitat utilization of the endangered Sonoran pronghorn (Antilocapra americana sonoriensis) on the Cabeza Prieta National Wildlife Refuge and the Organ Pipe Cactus National Monument in southwestern Arizona. Pronghorn groups were small (x = 2.5) and dispersed widely throughout the study area. I never saw Sonoran pronghorns drinking water. Cacti were the major diet components in the dry seasons. Forbs were the major diet component in the wet season. Cover, plants, and vertical obstruction was generally greater in occupied areas than in unoccupied areas. Plants in occupied areas were higher in protein than plants in unoccupied areas. The percentage of indigestible material (e.g., cellulose) in plants from occupied areas was generally less than in unoccupied areas. My data represent the characteristics of vegetation in areas used by Sonoran pronghorn. They could be applied in an intensive habitat management program to improve the quality of pronghorn habitat.