Kin recognition and mate choice in mice: the effects of kinship, familiarity and social interference on intersexual interaction

Abstract

Cross-fostered laboratory mice, Mus musculus, were tested for their ability to discriminate between individuals of the opposite sex on the basis of kinship. Subjects were presented with three sets of choices between familiar and unfamiliar test animals of five different degrees of relatedness. The three sets involved choices between (1) pots of soiled sawdust provided by test animals, (2) test animals confined within cages and (3) test animals in a freely mixing group. Analysis of time spent with different test animals or their odour cues and behavioural interactions between subject and test individuals showed evidence of kin discrimination by both sexes but discrimination was more pronouced in males and when subject and test animals were familiar. However, there was evidence of discrimination between unfamiliar animals in freely mixing groups. Males showed a preference for females of an intermediate degree of relatedness in terms of time spent and investigatory/contact activities but the little mounting behaviour that occurred appeared to be influenced by female proceptivity with females showing some preference for closely related (full/half-sibling) males. The difference in apparent preference between the sexes was similar to that reported in some other studies. There was no effect of male social dominance ranking per se on discrimination by females.