Improving Mule Deer Habitat Near Lander, Wyoming
By Carrie Dobey, Habitat Biologist, Wyoming Game and Fish Department
March 2008
Following the harsh winter of 1992-93, the South Wind River mule deer herd located in central Wyoming crashed to less than half of its 13,000 animal population objective and has never completely rebounded. The population in 2007 was estimated to be 10,000 animals. In 2003, the Wyoming Game and Fish Commission (WGFC) designated mule deer management as a priority for the Wyoming Game and Fish Department (WGFD). The Department selected the south Wind River herd as a model to observe how landscape scale habitat improvements could affect the population dynamics of the herd.
Regional wildlife biologists believed the primary cause for the low mule deer numbers was poor quality winter range. Years of drought, overuse and lack of fire has degraded large portions of the winter range. In 2004, a contractor was hired to map the vegetation across approximately 170,000 acres of winter range south and east of Lander, Wyo. As the contractor mapped the habitat types, over 200 potential habitat improvement projects ranging from sagebrush and juniper thinning to water developments were also identified. In 2007, the WGFD received $480,000 to implement the first phase of projects. Almost half of the funding came from the Wyoming Wildlife and Natural Resources Trust Fund, which was created in 2005 by the Wyoming Legislature. The trust is funded by interest earned on a permanent account, private donations, and legislative appropriations. The purpose of the program is to “enhance and conserve wildlife habitat and natural resource values throughout the state”. Remaining funds were received from several agencies and non-governmental organizations such as the Mule Deer Foundation, the Rocky Mountain Elk Foundation, the Wyoming Game and Fish Department, Bowhunters of Wyoming and Water for Wildlife.
Historically, juniper density was controlled by periodic wild fire, which kept the junipers in a savanna-type arrangement containing sparse junipers and plenty of grasses, forbs and shrubs between the junipers. As decades passed with no fire, the junipers became dense and out competed important deer browse, particularly antelope bitterbrush. By thinning the juniper, the WGFD’s goal is to improve the deer browse and increase overall winter survival of the herd. Another goal of juniper thinning is to increase the amount of grasses and forbs available in the early spring, which are critical to milk production. By removing the competition and providing more grasses and forbs, we hope to improve lactation of nursing does and therefore fawn survival.
Project implementation began in 2007 with 665 acres of juniper thinned using a hydro-buncher fitted with a vertical shaft mastication head. Thinning will continue in 2008 with a goal of an additional 1,000 acres to be treated. Future juniper projects will use prescribed burning to remove the plants in areas where the machine cannot maneuver. Unfortunately, cheatgrass has become prominent in several areas where prescribed fire is the preferred treatment option. These areas will be inspected closely prior to burns to determine if a burn should be completed and if herbicide treatments should follow burning to control the cheatgrass.
Juniper is not the only species that has become dense with the lack of wild fires. In several areas, sagebrush stands have become extremely thick, reaching up to 45% canopy cover in some places. Canopy cover greater than 25% begins to reduce the growth of grasses and forbs and the plant diversity and density eventually declines. The saying “variety is the spice of life” is particularly true when it comes to the vast expanses of sagebrush found in Wyoming. There are many areas in the winter range that are large, homogenous stands of one age class of sagebrush. A variety of age classes and densities of sagebrush are critical to the survival of many species including mule deer, pronghorn, sage-grouse, small mammals and song birds. For example, sage-grouse use older, more dense stands for nesting to provide protection from predators but use more open stands for early brood rearing when the chicks need insects. The more grasses and forbs present in an area, the more insects are available for chicks.
In the fall of 2008, nearly 2,300 acres of dense sagebrush will be thinned using the herbicide Spike (Tebuthiuron). The Spike pellets will be applied aerially with a goal of 50-60% sagebrush kill to reduce the shrubs to a more appropriate density. The applications will be done in mosaic patterns to increase the variety of densities and age classes of sagebrush. In addition to herbicide, we will also mow sagebrush in mosaic patterns to thin dense stands. Seventy acres within a 250-acre boundary were mowed in 2007. Monitoring transects were established in these treatment areas and will be read 1, 3 and 5 years post-treatment to observe changes in species richness, density and canopy cover.
Two wells will be upgraded to solar arrays in 2008. Excess water from these wells will be directed to basin areas that previously held water prior to the drought to create wetlands for use by deer, elk, pronghorn, sage-grouse and numerous other species. The wetland areas will be fenced with wildlife friendly fencing to prevent livestock trampling.
In addition to natural habitat degradation, human impacts have taken their toll on the herd as well. Housing development along the Wind River foothills is fragmenting critical winter range with no end in site. Several conservation-minded landowners have completed or are in the process of placing conservation easements on their property. A group of neighboring landowners has placed almost 3,000 contiguous acres into easements. This area protects not only mule deer habitat, but moose, elk and sage-grouse as well.
The next phase of the project will be focused on a new portion of the South Wind River winter ranges along the Beaver Creek drainage. There will be more juniper and sagebrush thinning as well as seeding, riparian improvements, water developments, fence modifications, weed control and improvements in livestock grazing management in cooperation with area landowners and public land managers. In its entirety, the Lander Front Mule Deer Habitat Improvement Project will take several years to complete and require multiple partners to continue its success.
As indicated by the author, partnerships are key and can also be successful within MDF. As an example, an additional $14,000+ will be allocated to this project in 2008. The sources of funds include a combination of chapter rewards and conservation partnerships from the MDF Wind River Chapter (Lander/Riverton WY), MDF Snowy Range Chapter (Laramie, WY), and MDF Central WY Chapter (Casper, WY). This is in addition to WY Governor’s Big Game License Coalition funds allocated to this project in 2007, which were raised by MDF Chapters.
