Sul Ross State University

Guzzler Use and Habitat Selection by Desert Bighorn Sheep
at Black Gap Wildlife Management Area, Texas

by Justin A. Foster, Michael T. Pittman and Louis A. Harveson

The development of artificial waters is often used to improve habitat for the advancement of desert bighorn sheep populations. However, there is dispute among researchers with regard to the benefits of water installments for enhancing desert bighorn sheep habitat. 

We investigated guzzler use by desert bighorn sheep (Ovis canadensis spp.) at seven sites on Black Gap Wildlife Management Area, Brewster County, Texas, with 35-mm remote cameras.

Desert bighorn sheep use (% composition of photographs) ranked third among 13 species documented and accounted for 29% (n = 412) of all photographs. In contrast to most literature, the majority of guzzler use by desert bighorn sheep (50%, n = 110) occurred between the hours of 1000 hr and 1600 hr.

Guzzler use was affected by precipitation and temperature with the majority of photographs (56%, n = 122) taken during the summer. Twenty percent (n = 87) of desert bighorn sheep guzzler use occurred during August, the summer month with the lowest recorded rainfall (1.7 cm).

The River 3 guzzler received the majority (73%) of all desert bighorn sheep guzzler use. The steepest slope (66%), farthest distance to another permanent water (9.1 km), lowest woody species canopy cover (15%), and lowest woody species density (1.9/ m2) characterized this guzzler.

Guzzler use by desert bighorn sheep increased as distance from the guzzler to another permanent water increased (P = 0.05, r2 = 0.90). Habitat variables including slope, canopy cover, screening cover and elevation were not related (P > 0.05) with desert bighorn sheep guzzler use.

The results of this study indicate that desert bighorn sheep utilize artificial waters during critical periods of high temperatures and low rainfall. The construction of guzzlers is an effective means of improving desert bighorn sheep habitat in Trans-Pecos Texas.

Cooperative funding provided by Texas Parks and Wildife Department, Texas Bighorn Society, Dallas Ecological Foundation, Houston Safari Club, San Antonio Livestock Exposition and Sul Ross State University.