Factors Affecting Diurnal Activity of Fishers in North-central British Columbia

Abstract

Mustelids, with their long, thin bodies and poor fat storage capabilities, perform an energetic balancing act when making decisions about energy expenditure. Activity rates provide vital insights into the factors that may affect these energy balances. Using radiotelemetry, we examined factors that affected the likelihood of diurnal activity of fishers (Martes pennanti) in north-central British Columbia, Canada. We assessed the effect of 7 biotic and abiotic factors on the activity of 13 radiotagged fishers by considering 17 models using an information-theoretic approach. The best model suggested that, during the snow-free season, diurnal activity in fishers increased with increasing ambient temperature. The model also predicted that the activity of males increased during the mating season, compared to nonmating periods, whereas activity decreased during the mating season for females without young. Females with young were less likely to be active than females without young. Thus, factors that changed over both short and long terms affected the diurnal activity of fishers. Identifying these factors provides us with a better understanding of how rates of activity, and thus energy expenditure, change through time.