Responses of Desert Bighorn Sheep to the Removal of Anthropogenic Water Sources

Abstract

Wildlife managers have assumed for years that the availability of free-standing water was a primary factor limiting the distribution, productivity, and recruitment of desert ungulates in the southwestern United States. As a result, wildlife management agencies and sportsman's organizations have invested significant time and resources in the construction and maintenance of water catchments for game species, including desert bighorn sheep (Ovis canadensis mexicana). Recently the efficacy of these catchments has been questioned and their use has become controversial. Although water catchments have been used as a wildlife management tool for decades, very few studies have experimentally examined the influence of these catchments on populations. The objective of this study was to experimentally examine the influence of water catchments on diet, movement, home range size, mortality, productivity, and recruitment of desert bighorn sheep.Part 1 involves the influence of the removal of water catchments on diet and characteristics of foraging areas used by desert bighorn sheep. Part 2 reports on the influence of the removal of water catchments on movement rates, home range size, and the distribution of desert bighorn sheep relative to water catchments. Part 3 involves the influence of the removal of water catchments on mortality, productivity, and recruitment of desert bighorn sheep. This study documents the response of desert bighorn sheep to the removal of water catchments and provides an understanding of how these catchments influence a bighorn population in southwestern Arizona