Arvicoline rodents (voles and lemmings) have rarely been studied in the field in winter. They do not migrate. They do not use torpor or hibernation to conserve energy. Yet they are the most abundant small mammals in arctic and sub-arctic ecosystems, surviving and reproducing in long, dark, cold and food-limited winters. There are no data on energy requirements of these animals in winter, no data on seasonal changes in their food quality and only indirect data available on reproduction outside summer. This project will be a field-based study on a representative species, the northern red-backed vole, Clethrionomys rutilus, in Alaska. It will substantially improve our knowledge of the mechanisms that underpin winter survival and reproduction in one of the most influential arctic taxa. Vole and lemming population sizes are of fundamental interest to ecologists working in arctic and sub-arctic ecosystems and this has been a driving force behind the search for the mechanisms that underpin their population cycles. Ecological work on population cycling has been handicapped by the absence of data on winter survival and reproduction rates. This project will generate those data and thus improve our ability to predict summer vole populations. It will help us to better predict the effect on winter reproduction and survival in vole and lemming populations should the current warming trend continue in Alaska. The aim of this project is to test the hypothesis that northern red-backed voles change their patterns of energy use and acquisition in winter in a manner that facilitates their survival and that these energetic changes enable a sub-set of the population to reproduce during that period. Field data on body condition, reproductive state and field metabolic rate will be obtained through the year from free-living voles in the Chugach State Forest, Alaska and correlations between these measurements and environmental parameters will be identified. Parallel laboratory studies will address what determines reproductive activity in winter. This project will help to establish a collaborative research network to broaden the related research infrastructure in Alaska. It represents the first major collaboration between the Alaska Zoo, Anchorage, Alaska, and the University of Alaska Anchorage (UAA). Display material and an educational program are being developed for the zoo to inform the general public about the research as well as on the general biology of Alaskan rodents. Research is a new focus for the Alaska zoo and its involvement represents a substantial increase in animal research infrastructure for Anchorage. This project will build collaborative links between Alaska's two major universities, the University of Alaska Anchorage and the University of Alaska Fairbanks, and will further the development of graduate research at UAA. The PhD student associated with this project is jointly enrolled at UAA and UAF and supervised by faculty from each campus. In addition to the PhD student and masters student employed in the project, at least one UAA undergraduate student will participate every summer through the UAA honors program and at least two Alaska Native High School students will do so as part of the Biomedical Department's Della Keats/UD0C program.
