SEASONAL AND DAILY ACTIVITY PATTERNS OF STRIPED SKUNKS (MEPHITIS-MEPHITIS) IN THE CANADIAN PRAIRIES

We investigated the hypothesis that the daily and seasonal activity pa tterns of female and male striped skunks (Mephitis mephitis) vary with reproductive constraints. Four biological periods were identified: pr e-parturition (1 April-14 May), parturition and rearing (15 May-30 Jun e), pre-dispersal (1-31 July), and dispersal (1-31 August). Tracking d ata (1873 h) indicated that activity (percentage time active) of femal e skunks varied among seasons, being lowest during the pre-parturition period (34 +/- 10%), and highest during the pre-dispersal period (66 +/- 4%). Male activity did not vary among seasons (55 +/- 3%). Animals of both sexes were mostly nocturnal, and had similar patterns of dail y activity. Onset and cessation of activity were highly variable, but were not affected by season or sex. Daily activity typically started 1 3 +/- 10 min before sunset, and was terminated 35 +/- 8 min before sun rise. Night-time activity periods of both sexes were often (57%, n = 1 08) interrupted by at least one resting period (median = 1, range = 0- 4). However, females rarefy (5%, n = 89) returned to the maternal den to rest. We hypothesize that the nocturnal activity of adults is linke d to prey activity and reduced predation risk, whereas apparent diurna l activity of juveniles represents an adaptation to daily fasting peri ods caused by the nocturnal foraging trips of females.