# Predicting Future Forage Conditions for Elk and Mule Deer in Montana and Wyoming

## Science Center Objects

Improving the quality of habitat for western big-game species, such as elk and mule deer, was identified as a priority by the Department of the Interior in 2018. Maintaining healthy herds not only supports the ecosystems where these species are found, but also the hunting and wildlife watching communities. For example, in Wyoming, big game hunting contributed over $300 million to the state’s ec... Improving the quality of habitat for western big-game species, such as elk and mule deer, was identified as a priority by the Department of the Interior in 2018. Maintaining healthy herds not only supports the ecosystems where these species are found, but also the hunting and wildlife watching communities. For example, in Wyoming, big game hunting contributed over$300 million to the state’s economy in 2015. Yet as climate conditions change, the quantity, quality, and timing of vegetation available to mule deer, elk, and other ungulates, known as forage, could shift. It’s possible that these changes could have cascading impacts on the behavior and population sizes of many species.

A key strategy used by managers to improve forage availability and adapt to change is the implementation of habitat treatments. These treatments include prescribed fire, forest thinning, and removal of invasive weeds, and are currently being planned to counteract the expected decline in mule deer habitat in the Kemmerer-Cokeville Area of southwestern Wyoming. To ensure that these activities are effective in meeting their goals, it is important for managers to have information on how forage conditions are already changing due to climate variability, and what any potential tradeoffs associated with these techniques may be.

Focusing on Montana and Wyoming, this project aims to meet this need by achieving three objectives. First, researchers will prepare summaries of past and future changes in forage by watershed, herd, and hunting area for both states. These summaries will help managers prioritize areas for management by providing baseline information about the direction, degree, and certainty of change in the quality and timing of forage. Second, researchers will assess changes in forage conditions in aspen, sagebrush, and mixed mountain shrub habitat in southwest Wyoming. They will develop maps of future forage based on scenarios that reflect probabilities of important weather patterns (such as drought), the current distribution of invasive cheatgrass (which decreases forage quality), and expected effects of planned habitat treatments, such as prescribed fire. Lastly, researchers will use these maps to evaluate the effects of treatment options on mule deer migration, fawning, and summer habitat, and on elk calving, migration, and habitat use.

The results of this project will be useful to a broad range of managers, including those with the states of Wyoming and Montana, and with federal agencies such as the U.S. Fish and Wildlife Service, the National Park Service, and the Bureau of Land Management. Successful management of elk and mule deer habitat will support healthy populations and ecosystems, as well as recreational opportunities that feed valuable revenue into local and state economies.