Quantifying the influence of climate change on Rocky Mountain ungulate populations, migration and feedground use, and herbivory impacts on vegetation
August 2008 - September 2010
- Global Change
In coming decades, society will be challenged to effectively manage important animal species as habitats and populations are altered due to climate change. In particular, many ungulates in the northern Rocky Mountains are predicted to respond to declining snow levels and increased drought, though in ways that remains uncertain. We will investigate how climate change, through altering precipitation regimes, may affect the abundance of Rocky Mountain ungulates, their migration patterns, the degree to which they transmit diseases to livestock, and their impact on certain key plants. Using large scale meta-analyses and computer simulations, we will assess the impacts of changing climate on the population dynamics of elk (Cervus elaphus), moose (Alces alces), mule deer (Odocoileus hemionus), bighorn sheep (Ovis canadensis), and pronghorn antelope (Antilocapra americana) populations. With previously collected data from GPS-collars, we will evaluate how the timing and routes of migration are influenced by the annual phenology of spring snowmelt, green-up, and winter severity. Combined with advanced epidemiological models, this information will help us assess how climate influences the time elk spend on winter feedgrounds, a key determinant of rate of transmission of brucellosis. Thus, the interaction between climate, elk feeding, and brucellosis transmission to cattle will be explored. Finally, preliminary evidence suggests that declining winter snow allows elk greater access to aspen during the winter, and could explain the widespread decline of these important trees. Monitoring elk herbivory, experimentally manipulating snow levels, and developing the first ever climate reconstruction of aspen based on previously-collected tree rings will allow us to evaluate how climate change impacts on elk foraging behavior, jointly with climatic forcing of aspen demography, influence future aspen regeneration.