Male rank and female choice in the bank vole, Clethrionomys glareolus.

This study aims to determine whether bank vole females selectively prefer the odour of a dominant male over that of a subordinate. The dominance rank of males was established by their aggression. The males that were considered dominants had higher aggression scores, measured as the sum of the number of attacks and pursuits. Dominants had sex accessory glands weighing significantly more than those of the subordinates, as a consequence of their higher plasma testosterone levels. In a two-choice test, naive females were more attracted to dominant males than to subordinates as manifested by the females' higher level of activity, more sniffs, and more time spent sniffing males of high rank. The same pattern of differences was noted when urine of dominant and subordinate males was used. The study provides some information about the female role in mate selection.