Personality, space use and tick load in an introduced population of Siberian chipmunks Tamias sibiricus

Abstract

1. Although behaviours can contribute to the heterogeneity in parasite load among hosts, links between consistent individual differences in behaviour and parasitic infection have received little attention. We investigated the role of host activity and exploration on hard tick infestations of marked individuals in a population of Siberian chipmunks Tamias sibiricus introduced in a suburban French forest over 3 years. 2. Individual activity-exploration profiles were assessed from 106 hole-board tests on 73 individuals, and chipmunks' trappability and trap diversity were used respectively as indices of their activity-exploration and space use on a sub-sample of 60 individuals. At each capture, we counted the total number of ticks per head of chipmunk. 3. We found significant and consistent individual differences in activity-exploration, trappability, trap diversity and tick load, and could estimate individual indices for these four variables, corrected for confounding effects of year, season, body mass and sex. 4. Using a path analysis, we found an indirect effect of activity-exploration on tick load: tick load increased with space use, which in turn was positively affected by trappability in the field. Trappability was itself positively related to activity-exploration in the hole board. Habitat type affected tick load, independently of behavioural traits. A second path model revealed a lack of either direct or indirect influence of tick loads on chipmunks' personality and trappability. 5. Our results show that host personality-related patterns in space use can lead to a non-random parasite distribution among hosts.