The contributions of genotype and sex to variation in mating behaviour between geographical subspecies of the bank vole (Clethrionomys glareolus scheber)

The sexual behaviour of bank voles from the mainland of Great Britain, and from the island of Skomer, differs in a number of respects. Voles from the mainland population show in general greater sexual activity. These variations may be understood as adaptations to ecological differences, particularly in population density. The reciprocal hybrids resemble the mainland population in a number of aspects of their mating behaviour. The possible evolutionary importance of this dominance is discussed. The behaviour of the bank vole is put into the perspective of generalizations made about other mammals. The separate influence of the male and of the female on quantitative variation between the two forms was investigated by studying mating between members of different populations. Some aspects of mating behaviour are shown to be due primarily to the male, others primarily to the female and others to the particular combinations involved. This situation is discussed in relation to the separate action of natural selection on members of each sex.