Cooperative Agreement with Partner of the Rocky Mountains Cooperative Ecosystem Studies Unit (CESU) Program.

The USGS is offering a funding opportunity to a CESU partner for developing research to
investigate multiple aspects of white-tailed ptarmigan biology (e.g., habitat use, demography, genetics) that are important for the management of this species that has been petitioned to be listed under the ESA. The white-tailed ptarmigan (Lagopus leucura) is the world’s smallest grouse species and a year-round resident in alpine habitats across the western United States, ranging from as far south as Colorado and New Mexico to Washington, extending across the Rocky Mountains in British Columbia and Alberta to Alaska. Species such as white-tailed ptarmigan that live in alpine habitats are vulnerable to changing climates because climate extremes can directly affect vital rates that underlie population persistence. Further, species residing on mountain tops have no opportunity to advance their range upward in elevation, in response to temperature changes. The southern subspecies has been studied at two long-term sites in Colorado (Rocky Mountain National Park and Mt. Evans) since the 1960s, and the Rocky population has been in severe decline. Spring densities and reproductive performance have remained extremely low through 2019 for the Rocky population, and reproductive declines have resulted in a population that is one third of historic highs observed in the 1970s.

Research is needed to better understand how ptarmigan resource conditions are affected by elk and human use in the alpine, assessing how ptarmigan may respond. Specifically, questions related to 1) developing a resource selection study that would identify crucial habitat for two populations in Colorado (Mt Evans, and Trail Ridge in Rocky Mountain National Park), 2) examining the impacts of elk and human recreational use on ptarmigan in Rocky Mountain National Park, and 3) evaluating the ability of ptarmigan to adapt for future environmental change. Further, these populations have already responded to warming springs by breeding earlier. It is unclear whether this is simply due to phenotypic plasticity or microevolution due to selection on heritable traits for earlier breeding. Thus, research is also required to examine whether variation in timing of reproductive behavior, resource quality within a given territory, and molt patterns is simply due to phenotypic plasticity or microevolution due to natural selection on heritable traits associated with those characteristics.