Behavioural syndromes in stereotypic striped mice

Abstract

Stereotypical behaviours (SBs) are abnormal, repetitive behaviours often observed in captivity. SBs are linked to impoverished captive conditions, and stereotypic individuals show a particular set of behaviours (e.g. bolder personality, greater activity) indicating proactive coping. Yet, we do not know whether SB is part of a behavioural syndrome, showing consistent individual variation in functionally different behaviours. We investigated the behavioural correlates of SB in the striped mouse Rhabdomys dilectus. Individual stereotypic and non-stereotypic mice were tested in four behavioural assays, including: (1) home cage behaviour; (2) dyadic encounters to assess social interactions; (3) response to novelty and risk- taking; and (4) routines (perseveration) in a plus maze. We predicted that SB is associated with proactive coping and higher levels of perseveration, and that stereotypic individuals will show a behavioural syndrome. Stereotypic striped mice showed higher levels of activity, whereas non-stereotypic mice displayed higher levels of hiding. Social motivation was not associated with the occurrence/absence of SB. Stereotypic striped mice engaged more with a novel object and were faster to return to previous behaviour after a startle than non-stereotypic mice, which displayed a reactive coping style. Levels of perseveration were higher in stereotypic striped mice. In stereotypic mice, SB was significantly positively correlated with activity, response to a novel object, risk-taking and perseveration, but not aggression. Non-stereotypic mice showed far fewer correlations. We showed that stereotypic and non-stereotypic striped mice differ in several behavioural phenotypes, possibly linked to common underlying neurobiological mechanisms. Moreover, stereotypic individuals, in particular, displayed a behavioural syndrome by demonstrating within-group correlations of behaviours in different contexts.