Resource dependence analysis of home range quality for pronghorn in south-central New Mexico, USA

Abstract

Pronghorn (Antilocapra americana) are challenged energetically in arid southwestern North American habitats; hence, identifying habitats that provide for their requirements is important to guide habitat management. We used resource-area-dependence analysis, which relates home range size to composition of home ranges, to determine habitats most associated with decreasing home range sizes (i.e., increasing quality) for pronghorn in south-central New Mexico, USA. Grama grasslands were most associated with home range quality for pronghorn, likely because grama grassland provided more forbs than other habitats, and forbs were the only forage class positively associated with pronghorn diet quality. Grama grassland also provided a diversity of browse, and the low structure facilitates visual detection of threats. Pinyon-juniper woodlands were marginally associated with home range quality of females, again because of relatively high diversity of forbs and browse. Pronghorn could benefit from management that increases diversity and abundance of forbs, such as burning during late-winter or early-spring to favor forbs over grasses and rejuvenate browse; this can also maintain an open canopy in woodlands. While precipitation will always be important for productivity and survival of pronghorn in arid southwestern environments, management that facilitates forbs could allow better forage responses to timely precipitation.