An observational analysis of Canada jay foraging and caching ecology in Denali National Park and Preserve-data

Abstract

Arctic wildlife are among the globe’s most vulnerable species to climate change. Canada jays are generalist residents of northern boreal forests, and like many other winter-adapted animals, scatter hoard food to insulate against food scarcity during long winters. Unlike most scatter-hoarders, however, Canada jays primarily cache perishable food, rendering their caches more susceptible to climate-change induced degradation and loss. Here we use a mostly non-invasive approach to document Canada jay foraging ecology, including the types of food acquired, foraging and caching rates, and cache longevity and loss, among a population in interior Alaska. We also tested for any associations between foraging and caching rates with reproductive metrics to assess possible relationships among food and productivity. We found that Canada jays have a varied diet that changes seasonally, and responded to a record-setting warm spring by directing foraging efforts away from cache recovery towards the emergence of fresh food. We did not find evidence for relationships between foraging and caching rate with reproductive output, possibly owing to small sample sizes. We found that caches were recovered quickly (<3w) and frequently lost to conspecifics, and interestingly, to heterspecific competitors as well. Our study suggests that Canada jays may be better poised to respond to changes in cache integrity and food availability than has been previously recognized.