Mule Deer Biology

Managing Desert Mule Dee
Texas Agricultural Extension Service * Zerle L. Carpenter, Director * The Texas A&M University System * College Station, Texas

Managing Desert Mule Deer

Dale Rollins
Extension Wildlife Specialist
The Texas A&M University System

Photo courtesy of the Texas Parks and Wildlife Department Desert mule deer (Odocoileus hemionus crooki), also known as “blacktails” or “muleys,” are important big game animals in the Trans-Pecos and Panhandle regions of Texas. For the period 1978-88, the number of mule deer in Texas ranged from a low 149,000 in 1983 to a high 245,000 in 1986. The average figure is about 207,000 with about 90 percent being found in the Trans-Pecos region (Fig.1).

Mule deer are found throughout the Trans-Pecos and along the western portion of the Edwards Plateau near the Pecos River. During the 1950s and 1960s, mule deer were transplanted into the Palo Duro Canyon and surrounding areas of the “caprock” and have since become well established. In the Panhandle, mule deer are found in disjunct populations along the rolling hills and canyons associated with tributaries of the Brazos, Canadian and Red Rivers and along the caprock escarpment.

Mule deer are an important resource because the demand for hunting is high and the income generated from hunting leases has been an important component of ranch income for most ranchers in the Trans-Pecos region. Their economic value has prompted many ranchers to become more aware of the management needs for mule deer. Indeed, many land use decisions (for example, livestock stocking rate, water developments, brush control) can have a major impact on mule deer. The extent of the impact, and whether it is positive or negative, depend primarily on the degree to which wildlife requirements were considered.

 Desert mule deer range in Texas.Deer management, like livestock management, varies from one ranch to another depending upon land characteristics and the rancher’s objectives. Just as some areas have a higher grazing capacity for cattle, some areas have a higher carrying capacity for mule deer, antelope, etc. In its simplest form, deer management involves three principles: (a) habitat management; (b) population management; and (c) people management. Obviously, each of these will affect the others.

First and foremost, the presence of suitable habitat determines where and in what abundance mule deer will be found. Generally, habitat management involves plant management, the two key points being: (a) knowing what plants are important for mule deer food and cover; and (b) knowing how to manipulate them. For rangeland habitats in West Texas, management tools may include grazing practices, brush management, water development, prescribed burning and receding operations.

Next in importance is population (herd) management. This means keeping the population in balance with the habitat’s carrying capacity. It also involves manipulating the age and sex ratios, herd density and other factors affecting population growth (predation, migration, competition with white-tailed deer and exotics).Generally, population management centers around regulating harvest levels. Problems have arisen in the past when biologists and ranchers tried to apply white-tailed deer management (specifically Hill Country deer management) to desert mule deer. Such strategies have caused concern in regarding (a) spike buck management, (b) doe management, and (c) overall harvest rates. There is a lack of definitive movement patterns and other population-related phenomena (natural mortality, competition with livestock) which continues to hamper mule deer management in West Texas. Recognizing this, the state legislature recently appropriated funds for the Texas Parks and Wildlife Department for additional research on mule deer.

Finally, people management is important because it is the means for managing populations (i.e., sport hunting). Working with the public, even the paying public, is often a real headache. However, as sport hunters are the primary consumers, it’s very important to understand their needs.