Dissipation of kin discrimination in Orkney voles, Microtus arvalis orcadensis: A laboratory study

Field experiments testing the roles of relatedness in vole demography make different assumptions on the ability of voles to recognize their unfamiliar kin and this may have contributed to their contrasting outcomes. We measured the rate of dissipation of discrimination between related male and between related female Orkney voles (Microtus arvalis orcadensis) after increasing periods of separation to test these assumptions. Females showed a decreasing preference for the odour of their sisters as familiarity for new cage-mates increased and an increasing preference for their new cage-mates as familiarity increased. In contrast, males showed no such changes in their avoidance of their brothers following separation. Dissipation of kin-discrimination by Orkney voles in absence of reinforcement by familiarity is therefore rapid and familiarity established in adult life seemingly has the same impact on preference between females as relatedness.