Home Ranges of Pronghorn in the Trans-Pecos Region of Texas

Abstract

We determined home ranges of pronghorn (Antilocapra americana) over a 3-year period in the Trans-Pecos region of Texas. Male pronghorn consistently had smaller (P<0.05) home ranges than females; males (n=8) and females (n=28) averaged 25.1 ± 4.5 (SD) and 42.4 ± 10.1 km², respectively. Drought conditions influenced home ranges of females. In 1990, a year of below average precipitation, home ranges of females (n=36) during post-fawning (18 Jun to 20 Aug) were larger (P<0.05) than female home ranges (n=36) during fawning (15 Apr to 17 Jun), averaging 32.5 ± 14.5 and 17.1 ± 8.3 km², respectively. During 1991, a year of above average precipitation, female home ranges were similar (P>0.05) between fawning and post-fawning periods. Home ranges of females during the fawning season were similar (P>0.05) between 1990 and 1991. However, in 1990 females during the post fawning season had larger (P<0.05) home ranges than those in 1991, averaging 32.5 ± 14.5 and 20.4 ± 6.2 km², respectively. We concluded that pronghorn in the Trans-Pecos require larger home ranges than pronghorn occurring in more optimal habitats of their geographic range, that females require larger home ranges than males, possibly related to greater nutritional demands, and that monthly precipitation, which affects forage quantity and quality, influences home range size for females, particularly during the post fawning period.