Activity of eastern chipmunks (Tamiasstriatus) 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.

Behavioral classification of low‐frequency acceleration and temperature data from a free‐ranging small mammal

“…This includes in (black bars) and out (gray bars) of the nest in the temperature data during both winter and summer, and running, feeding, not moving, and foraging signatures in acceleration data temperature can provide important supplementary information about an individual and its thermal micro-environment. However, depending on the ecology of the species and which of these two temperatures vary more, collar temperature can be used to monitor thermal exposure (Osgodd & Weigl, 1972;Kanda, Fuller, & Friedland, 2009) or heterothermic fluctuations indicative of torpor expression or hibernation (Lazerte & Kramer, 2016). This temperature intermediacy likely accounts for their rarity of use; collar temperature is not a reliable measure of body temperature or air temperature (Audet & Thomas, 1996;van Beest, Moorter, & Milner, 2012).…”

“…This temperature intermediacy likely accounts for their rarity of use; collar temperature is not a reliable measure of body temperature or air temperature (Audet & Thomas, 1996;van Beest, Moorter, & Milner, 2012). However, depending on the ecology of the species and which of these two temperatures vary more, collar temperature can be used to monitor thermal exposure (Osgodd & Weigl, 1972;Kanda, Fuller, & Friedland, 2009) or heterothermic fluctuations indicative of torpor expression or hibernation (Lazerte & Kramer, 2016). Most pertinent here, collar temperature likely offers useful information about behavioral state, as it tends to more closely approximate the body temperature of inactive animals confined in small spaces (e.g., thermal refuges) and to more closely approximate the air temperature experienced by active animals fully exposed to ambient conditions (Körtner & Geiser, 2000;Messier, Taylor, & Ramsay, 1994;Murray & Smith, 2012;Olson et al, 2017;Wassmer & Refinetti, 2016).…”

Spatio-temporal variation in oxidative status regulation in a small mammal

“…They then shift to hoarding red maple seeds in mid-summer as the spring plant disappear and the red maple seeds start falling (Elliott, 1978). During late summer, as in previous mast years, red maple seed depletion resulted in a decrease in food availability and reduced above ground activity, which lasted until beech seed masting in early fall (LaZerte & Kramer, 2016). Thus, a general decrease in food availability may be linked with a shift in oxidative status regulation observed in the studied adult population.…”

“…However, a closer analysis of spring populational mass did not show different mass gain rates between males than females (Table S5). Yet, females may not spend as much time in euthermia before emergence, possibly to benefit from conserving their food reserves for future gestation and lactation (Munro, Thomas & Humphries, 2005), which can occur during a low food availability period (Elliott, 1978; LaZerte & Kramer, 2016; Munro, Thomas & Humphries, 2005). Females, therefore, possibly experienced a shorter restoration period compared to males, which may have impaired oxidative status regulation.…”

Behavioral Responses of Wild Rodents to Owl Calls in an Austral Temperate Forest

“…Lastly, understanding how rodent responses vary locally and temporally also requires further research. Rodents may behave differently in urban, rural and well-preserved native habitats [67], and seasonality may also be relevant to changes in rodent behavior [68,69].…”