DESERT MULE DEER RESEARCH

POPULATION TRENDS

Survival, Movements, and Habitat Use of Translocated Desert Mule Deer in Southeastern Brewster County, Texas

John Clayton Kiddo Campbell, Louis A. Harveson, and Shawn Gray (TPWD)

Over the last century, mule deer (Odocoileus hemionus) in Texas have varied in distribution and population size. Their ranges expand across the western half of Texas, however, the mule deer population in the Trans-Pecos region has fluctuated since the late 1980s with portions never fully recovering in population size. In 2015 and 2016, Texas Parks and Wildlife Department and partners translocated a total of 116 mule deer does to southeastern Brewster County. Mule deer were translocated from Elephant Mountain Wildlife Management Area and two other source populations, to the Black Gap Wildlife Management Area (soft-release) and El Carmen Land and Conservation Company (hard-release) properties. These areas are collectively called the Black Gap Complex.

From both release years, survival was slightly higher amongst hard-released individuals (73% and 56% survival rates for 2015; 78% and 63% survival for 2016). However, during these two years, soft-released deer exhibited higher site fidelity to the release site. The soft-release also produced smaller core and general utilization distributions. We also found no difference in range sizes relative to release method. Translocated mule deer had higher usage in five habitat classifications within their home ranges. These five included, the Chihuahuan Succulent Desert Scrub, Chihuahuan Mixed Desert and Thornscrub, Apache-Chihuahuan Semi-Desert Grassland and Steppe, North American Warm Desert Riperian Woodland and Shrubland, and the North American Warm Desert Wash.

Of these habitat classification areas, only Chihuahuan Succulent Desert Scrub, Chihuahuan Mixed Desert and Thornscrub, and Apache-Chihuahuan Semi-Desert Grassland and Steppe, were used by mule deer in higher proportions than available within the core ranges. Because these areas were being used in higher portions, they are of particular interest for future mule deer habitat management efforts at the Black Gap Complex.

Funding sources: Mule Deer Foundation, Houston Safari Club, West Texas Chapter of the Safari Club International, San Antonio Livestock Exposition, Texas Parks and Wildlife Department, and CEMEX