Contest winning and metabolic competence in male bank voles Clethrionomys glareolus

Famale bank voles prefer dominant males as mates, and it has been suggested that this preference may benefit females genetically, via increased fitness of their progeny. This requires that male ability to win intrasexual contests is associated with their genetic quality. An important aspect of individual quality is metabolic competence. Here, we investigated whether male ability to win contests is correlated with aerobic capacity (the maximum rate of oxygen consumption) or factorial aerobic scope (the ratio of aerobic capacity to basal metabolic rate [BMR]). The ability to win was assessed as proportion of dominant behaviours in staged contests with five other males, and aerobic capacity was measured both during exercise (swimming) and during cold-exposure trials. Contest winning ability was not correlated with the aerobic capacity (p > 0.6), the factorial metabolic scope (p > 0.25) or BMR (p = 0.24; all the traits were corrected for the effect of body mass). Thus, the results indicate that the trait (male dominance) subject to female preference in the bank vole fails to reveal an important aspect of male quality, i.e. his metabolic competence.