Spatial navigation strategies in Peromyscus: a comparative study

A male advantage in spatial abilities is predicted to evolve in species where males rely on expansion of home territory to locate dispersed mates during the breeding season. We sought to examine mechanistic underpinnings of this evolved trait by comparing spatial navigational abilities in two species of Peromyscus that use widely different reproductive strategies: deer mice, Peromyscus maniculatus bairdii, in which males engage in territorial expansion and mate search, and California mice, Peromyscus californicus insignis, in which males do not engage in territorial expansion and mate search. Males and females from outbred stocks of each species were administered tasks that assessed spatial learning and memory, and activity and exploratory behaviours. The maze used for these studies included four spatial cues that could be used to aid in locating one of 12 potential escape holes. As predicted, male deer mice outperformed conspecific females and male California mice in maze performance and memory, and this difference appeared to be due to extent to which animals used spatial cues to guide maze navigation. Consistent with territorial expansion as a component of competition for mates, male deer mice were more active and engaged in more exploratory and less anxiety-related behaviours than conspecific females and male California mice. The results have implications for understanding and studying the cognitive and behavioural mechanisms that have evolved through male-male competition that involves territorial expansion and mate search. (C) 2012 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.