Accelerometry data (1hz) for arctic ground squirrels3-Axis accelerometry data (File 1 of 3; split) for arctic ground squirrels (collar mounted accelerometer) sampled at 1HZ. File includes individual identifier (uniqueID), sex, location ([Atigun; 68º27’ N, 149º21’ W; elevation 812 m] or Toolik [68º38’ N, 149º38’ W; elevation 719 m]), and calculated ODBA (overall dynamic body acceleration) for each second.accelerometry2.csv.001Accelerometry data (1hz) for arctic ground squirrels file 23-Axis accelerometry data (File 2 of 3; split) for arctic ground squirrels (collar mounted accelerometer) sampled at 1HZ. File includes individual identifier (uniqueID), sex, location ([Atigun; 68º27’ N, 149º21’ W; elevation 812 m] or Toolik [68º38’ N, 149º38’ W; elevation 719 m]), and calculated ODBA (overall dynamic body acceleration) for each second.accelerometry2.csv.002Accelerometry data (1hz) for arctic ground squirrels file 33-Axis accelerometry data (File 3 of 3; split) for arctic ground squirrels (collar mounted accelerometer) sampled at 1HZ. File includes individual identifier (uniqueID), sex, location ([Atigun; 68º27’ N, 149º21’ W; elevation 812 m] or Toolik [68º38’ N, 149º38’ W; elevation 719 m]), and calculated ODBA (overall dynamic body acceleration) for each second.accelerometry2.csv.003Light logger data for arctic ground squirrel - Migrate 20142014 Light logger data for arctic ground squirrels (collar mounted accelerometer) from Intigeo geolocators (Migrate Technology Inc). File includes individual identifier (uniqueID), sex, and location ([Atigun; 68º27’ N, 149º21’ W; elevation 812 m] or Toolik [68º38’ N, 149º38’ W; elevation 719 m]).migrate2014_2.csvLight logger data for arctic ground squirrel - Migrate 20152015 light logger data for arctic ground squirrels (collar mounted) from Intigeo geolocators (Migrate Technology Inc). File includes individual identifier (uniqueID), sex, and location ([Atigun; 68º27’ N, 149º21’ W; elevation 812 m] or Toolik [68º38’ N, 149º38’ W; elevation 719 m]).Migrate_2015.csvLight logger data for arctic ground squirrel - Biotrack 2014Light logger data for arctic ground squirrels (collar mounted) using m-series geolocator by Biotrack. File includes individual identifier (uniqueID), sex, and location ([Atigun; 68º27’ N, 149º21’ W; elevation 812 m] or Toolik [68º38’ N, 149º38’ W; elevation 719 m]).bas2014_2.csvLight logger data for arctic ground squirrel - Biotrack 2015Light logger data for arctic ground squirrels (collar mounted) from m-series geolocator (Biotrack). File includes individual identifier (uniqueID), sex, and location ([Atigun; 68º27’ N, 149º21’ W; elevation 812 m] or Toolik [68º38’ N, 149º38’ W; elevation 719 m]).bas2014_2.csvWeather Data Atigun River - 2014Weather data (April 1 - August 15, 2014) for site adjacent to Atigun River (68º27’ N, 149º21’ W; elevation 812 m). Hobo U30-NRC weather station (Onset Computer Corporation, Bourne, Massachusetts). Rain Gauge is a tipping bucket.Atigun_Weather_Apr_Aug2014.xlsxWeather Data Atigun River - 2015Weather data (April 27 - June 10 2015) for site adjacent to Atigun River (68º27’ N, 149º21’ W; elevation 812 m). Hobo U30-NRC weather station (Onset Computer Corporation, Bourne, Massachusetts). Rain Gauge is a tipping bucket.Atigun_Weather_Apr_Jun2015.xlsxArctic ground squirrel body mass data 2014-2015Body Mass data for arctic ground squirrels captured at site adjacent to Atigun River (68º27’ N, 149º21’ W; elevation 812 m) or adjacent to Toolik Lake (68º38’ N, 149º38’ W; elevation 719 m).Body_Mass_2014_2015.xlsx

The sexes differ in how and when they allocate energy towards reproduction, but how this influences phenotypic plasticity in daily activity patterns is unclear. Here, we use collar-mounted light loggers and triaxial accelerometers to examine factors that affect time spent above ground and overall dynamic body acceleration (ODBA), an index of activity-specific energy expenditure, across the active season of free-living, semi-fossorial arctic ground squirrels (Urocitellus parryii). We found high day-to-day variability in time spent above ground and ODBA with most of the variance explained by environmental conditions known to affect thermal exchange. In both years, females spent more time below ground compared with males during parturition and early lactation; however, this difference was fourfold larger in the second year, possibly, because females were in better body condition. Daily ODBA positively correlated with time spent above ground in both sexes, but females were more active per unit time above ground. Consequently, daily ODBA did not differ between the sexes when females were early in lactation, even though females were above ground three to six fewer hours each day. Further, on top of having the additional burden of milk production, ODBA data indicate females also had fragmented rest patterns and were more active during late lactation. Our results indicate that sex differences in reproductive requirements can have a substantial influence on activity patterns, but the size of this effect may be dependent on capital resources accrued during gestation.