Recognition of kin in bank voles (Clethrionomys glareolus).

The ability of animals to recognise their kin plays an important role in sexual selection. This study addressed the question of whether there is sibling recognition between young and adult bank vole females and males, and if so, how kin are recognised. The behavioural data from these experiments show that bank vole females can recognise their sibling brothers on the basis of their odours. In two-choice preference tests, prepubertal females were more attracted to the scent of socially known sibling and foster brothers than to the scent of unfamiliar males or of sibling brothers cross-fostered at birth and reared in a different nest. The females' odour preferences shifted with age. Mature females preferred the novel odour of unrelated males to that of sibling brothers regardless of whether the latter were reared with or apart from the tested females. These results indicate that two mechanisms of kin recognition co-exist in bank voles. Prepubertal females used a familiarity-based mechanism (recognition by social association) and adult used phenotype matching (genetic mechanism). The implications of these findings for bank vole biology are discussed.