Climatic shifts to warmer and often drier conditions are occurring more rapidly at higher elevations and latitudes, and are therefore likely to disproportionately affect the mammalian hibernators that occur there. In general, hibernator active seasons are lengthening, as hibernation phenology tracks shorter winters. However, we still lack a mechanistic understanding of how these longer active seasons are affecting intraspecific life history variation such as accelerated juvenile growth and rate of maturity; these processes are key to predicting both individual fitness, population-level resilience, and species persistence. Are juvenile squirrels able to track changing vegetation phenology associated with shorter winters- by increasing amount of time spent foraging, and/or changing diet of plants consumed – or not? We will use an elevational gradient, with associated differences in growing season length and phenology, to compare (1) activity budgets (i.e. proportion of time spent foraging), (2) diet diversity, and (3) growth rates of juvenile ground squirrels in the weeks following emergence from the natal burrow.
