Funded Research Projects: WILDLIFE SCIENCE

Foraging Ecology of the Gray Jay in a Changing World

Research Sponsored By: USDI National Park Service
Principal Investigator: John Marzluff
Project Description
Gray Jays are common birds in northern forests, but in some locations their abundance is declining, possibly reflecting the challenges of living in a warmer climate. The mechanisms hypothesized linking warming temperature to population declines include: 1) increased spoilage of cached foods as winter climates warm (jays use mostly cached foods to fuel late winter reproduction); 2) reduced reproductive success on territories experiencing rotting of caches. I will cooperate with NPS investigators to study this possibility in Denali National Park. Specifically, I will study the foraging and caching behavior of jays to determine what foods are stored and how susceptible they are to spoilage in warming conditions. I have 8 objectives: 1. Coordinate activities with the NPS to maintain a marked population of jays in and around Denali National Park, Alaska. 2. Augment the fieldwork of NPS staff to annually to determine the territory size, breeding success, and annual survival of marked jays. 3. Observe the foraging behavior of territorial jays (including adults and young that remain in the natal territory) to document the diversity of items consumed and cached by jays. 4. Observe the foraging behavior of territorial jays to document individual variation in the relative composition of the jays’ diets. 5. Observe the foraging behavior of territorial jays to document the locations in which food items are cached. 6. Monitor a selection of caches made by jays to determine the length of time caches exist and the frequency of cache retrieval. 7. Determine the extent to which variation in caching and foraging drive differences in the timing and success of reproduction. 8. Perform experiments to determine dietary and caching preferences.