Meeting Abstract
As the northern-most hibernator in North America, the arctic ground squirrel must reproduce, molt, and fatten for the subsequent hibernation cycle during a comparatively short 3-5 month active season. The timing of peak energy allocation to reproduction differs between males and females, with males peaking shortly after hibernation and females peaking some weeks later during gestation and lactation. We hypothesized that sex-specific differences in energy allocation to reproduction would be reflected in above-ground (foraging) and below-ground activity with weather events providing a significant, but lesser, impact on activity patterns. We recorded patterns of above- and below-ground activity of free-living adult male and female arctic ground squirrels with collar-mounted light loggers and collected environmental data using local meteorological stations. All animals showed dramatic fluctuations in time spent above-ground each day, which correlated to environmental conditions including ambient temperature, precipitation, and windspeed. Unexpectedly, sex had only a minor influence on patterns of above-ground activity with the exception that during the early breeding period, males were more active. Despite the energetic requirements of gestation and lactation, activity patterns of reproductive females were remarkably similar to both non-reproductive females and males. Thus, daily changes in environmental conditions exert a much greater influence on patterns of above-ground activity than reproductive status or sex.
