Does parasite infection affect mouse personality traits and behavioural syndromes? (#183)
Parasitism may affect animal personality traits and behavioural syndromes in subtle ways, which may be overlooked by comparing mean trait values between infected and uninfected groups. Infection may alter host personality by changing the consistency of a host’s behavioural response over time, or may affect behavioural syndromes by decoupling behavioural traits or changing the way they correlate with each other. This study aimed to test these predictions in a Toxoplasma gondii-mouse model. It is believed that T. gondii manipulates a range of behaviours in rodents to make them more likely to be caught by cats, thus increasing transmission of the parasite to its definitive host. However, individual differences in behaviour have rarely been considered. We assessed individual behaviour of experimentally infected and uninfected female laboratory mice in three behavioural tests (the elevated plus maze; EPM, and the open field; OF, and a predator odour avoidance arena; POAA) at five time points over 6 months. We characterised mouse personality using exploratory factor analysis to define two main factors for the EPM and OF; EPM activity, EPM boldness, OF activity and OF boldness. We also examined individual differences in the response to predator odour (cat urine). Our results indicate that uninfected mice show repeatable individual differences in personality traits (activity and boldness) over time and in different contexts. Individuals also differed in their response to cat urine. Although infection with T. gondii did not cause mice to lose their aversion to cat urine, results suggest that infection may affect an individual’s side preference in an arena and alter the way in which personality traits correlate with each other.