Anxiety and exploratory behavior in the African striped mouse, Rhabdomys, taxa are partially modified by the physical rearing environment.

Abstract

The environment may modulate genetic influences on behavioral expression. We investigated whether the physical rearing environment modulates anxiety and exploratory behavior in four populations, representing three species, of the striped mouse Rhabdomys. One population originated from an arid, open habitat and the others from grassy, covered habitats, and two species occurred in sympatry. We raised captive individuals of all populations in treatments that simulated cover or no cover for two generations and investigated the behavior of resulting adults in an open-field, light-dark and startle response tests. We expected that, when raised without cover, the arid population would be less anxious and more exploratory than grassland populations, but found the opposite in the open-field test only. We also expected that all individuals would be anxious and less exploratory when raised under cover, which was the case for anxiety in a light-dark test, but individuals from the no cover treatment were more anxious in the open-field test. Only one population × treatment interaction was detected in which the arid population was least exploratory. Therefore, the physical rearing environment had less of an influence than phylogeny on the development of anxiety and exploration in Rhabdomys.