Temperament, risk assessment and habituation to novelty in eastern chipmunks, Tamias striatus

An increasing number of studies are focusing on the role of animal temperament in the ecology of wild populations. One important step in these studies is to estimate the repeatability of temperament traits, by replicating measures of an animal's behavioural or physiological reactions to a novel or stressful situation. When studies are performed in the field, several factors can affect repeatability estimates: (1) microenvironmental conditions prior to or during a test may affect the measured behaviour, and spatial heterogeneity in predation risk within the habitat of a population may affect repeatability; (2) a decrease over time in the strength of behavioural reactions as a result of habituation may bias repeatability; and (3) individuals may differ in their habituation. In this study we used a linear mixed-model approach to test for the occurrence of interindividual variation in behavioural reaction and habituation of eastern chipmunks, Tamias striatus, to a hole-board test and a handling bag test. We found high intraindividual consistency for the behaviours recorded both in the hole-board and handling bag tests; four temperament traits could be considered (i.e. activity/exploration, reaction to stress, emotionality and docility). Given that we found no phenotypic variation in habituation, chipmunks seem to show a behavioural carryover in activity/exploration and docility, which could have consequences for the evolutionary potential of habituation to novelty