Male dominance and female chemosensory preferences in the rock-dwelling snow vole

The aim of this study was to examine how factors affecting male scent attractiveness to females interact with factors influencing male social dominance in rock-dwelling snow voles, Chionomys nivalis. We analysed the effect of particular phenotypic traits of male fitness, including relative body weight, bilateral asymmetry levels and haematocrit volume, upon relative success at both intra- and intersexual processes (measured as the outcome of social interactions among males and the level of attraction of males' odours to females, respectively). We found that males achieving more dominant status were those of higher relative body weight, which may give them physical advantage in intrasexual contests. Although social status of experimental males was not directly influenced by haematocrit volumes or levels of asymmetry, data from their original population indicate that relative heavier males are indeed more symmetric than lighter males. Regarding the attractiveness of male's odours, results show that relative body weight was unimportant to females, which principally favoured scents of individuals with higher haematocrit volumes. In addition, females tended to be more attracted towards the scents of less asymmetric males. These findings suggest that relative success of male C. nivalis at intra- and intersexual levels might be influenced by different factors. Nevertheless, due to the tight interrelationship between traits of male fitness, attraction to females and achievement of dominant status may not be completely independent. We further hypothesize that intrinsic information contained in male odour cues could be adaptively, and differently, used by conspecifics of both sexes in this species.