Is wheel running a re-directed stereotypic behaviour in striped mice Rhabdomys dilectus?

Abstract

When given the opportunity, many captive animal species make use of a running wheel. Wheel running is often used as an environmental enrichment to increase general locomotor activities. Yet, it is still debated whether wheel running is an enrichment or a stereotypic behaviour. Here, we investigated the motivation to use a running wheel in African striped mice. Individual striped mice showing locomotory stereotypy or were non-stereotypic were exposed randomly to three different treatments in which we restricted space for displaying stereotypy in a 1) home cage, 2) an attached experimental cage, or 3) space was unrestricted in both cages. Individuals spent 15 days in each treatment, during which we recorded their behaviour every second day. We also accounted for personality in the use of running wheels. Stereotypic striped mice were more active (i.e. non-stereotypic activity) and used the running wheel more than non-stereotypic individuals, which were less active. Half (52%) of the stereotypic mice incorporated the running wheel in their stereotypic routine, and the remaining 48% used the running wheel as part of their general activity. Furthermore, while wheel running may have reduced stereotypic behaviours in the striped mice that used it as enrichment, it was not solely responsible for the reduction. The combined effect of cage complexity and the running wheel acted in synergy in reducing stereotypic behaviours, as shown by an increase in general activity. Personality considers intra-individual consistency and inter-individual variation, yet individual stereotypic striped mice showed varied behavioural responses to the running wheel, contrary to the personality theory. Thus, implementing a running wheel should be tailored for identified individuals rather than a species-wide implementation.