The Impacts of Drought on Fish and Wildlife in the Southwestern U.S.

Species that inhabit the arid Southwest are adapted to living in hot, dry environments. Yet the increasing frequency and severity of drought in the region may create conditions that even these hardy species can’t survive. This project examined the impacts of drought in the southwestern U.S. on four of the region’s iconic species: desert bighorn sheep, American pronghorn, scaled quail, and Rio Grande cutthroat trout. Grasping the impacts of drought on fish and wildlife is critical for management planning in the Southwest, as climate models project warmer, drier conditions for the region in the future.
 
Species are known to respond to environmental changes such as drought in different ways. Often, before changes are observed at the larger population level, they are first noticed at the level of the individual, through changes in an animal’s behavior. For example, when vegetation becomes harder to find during a drought, individuals may increase the amount of time and energy they spend searching for food. If changes in behavior such as these are not sufficient to compensate for the lack of vegetation, the population as a whole could eventually experience decreased survival and reproductive rates.
 
Through four sub-projects, researchers worked to improve our knowledge of individual behavioral changes (in the case of desert bighorn sheep) and overall population changes (for pronghorn, trout, and quail) that occur in response to drought.