Activity of eastern chipmunks (Tamias striatus) during the summer and fall

Abstract

Measuring activity of small mammals in the field is challenging because they are often out of view. We used a novel method, based on temperatures of collar radio transmitters, to quantify the proportion of time eastern chipmunks (Tamias striatus (L., 1758)) spent active, curled up resting, and torpid during the summer and fall of 2 years in southern Quebec. Time active over the 24 h day was lower in a nonmast (8%) than a mast (26%) year. In the mast year, activity varied strongly from a low of 7% during the summer lull to a high of 35% in the fall. Chipmunks that exploited a feeder had higher activity (33%) than chipmunks that did not (19%). Activity was higher during the day, but some activity occurred at night. Daily activity patterns varied strongly among seasonal periods. There was no evidence of torpor during the summer lull. Torpor started much earlier in the nonmast than in the mast year and occurred more at night than during the day. Overall, our study suggests that activity in this food-storing hibernator is positively influenced by food availability and indicates that thermosensitive radiotelemetry is a promising method for recording continuous activity.