HERITABILITIES OF DOMINANCE-RELATED TRAITS IN MALE BANK VOLES (CLETHRIONOMYS GLAREOLUS)

A number of studies have shown that in several animal species females prefer dominant males as mating partners, but fewer attempts have been made to measure possible indirect benefits of this choice. One reason for this may be that, even though dominance is a widely used concept, the definition of dominance still remains controversial Furthermore, defining and measuring the heritability of social behaviors is problematic because they are not individual traits but, by definition, involve interactions between at least two individuals. In this study we estimated heritabilities and coefficients of additive genetic variances (CV_A) for male traits that are closely associated with dominance and female mating preferences in bank voles (Clethrionomys glareolus). The heritability values were estimated using father-offspring regression. All heritability estimates were relatively high ranging from 0.531 (urine marking) to 0.767 (preputial glands). The CV_A-values indicated high levels of additive genetic variance especially in the characters most closely related to dominance: the weight of preputial glands and urine marking behavior. All phenotypic correlations among the traits measured were significantly positive and the genetic correlations were of similar magnitude as the corresponding phenotypic counterparts. Even though heritabilities may be lower in the natural environment than under controlled laboratory conditions, our results suggest that characters closely related to dominance may be at least partly genetically determined.