Dominance in Intermale Encounters and Subsequent Sexual Success in Mice

In Experiment 1, when previously isolated male mice were paired and given a female, they fought before beginning to mount, and the more aggressive male ejaculated somewhat more frequently. Males housed together for several days showed little aggression when jointly given a female, but those that were more aggressive in the home cage clearly ejaculated more frequently. In Experiment 2, males were paired for 4 days after a period of isolation. More aggressive males showed more ejaculations when subsequently tested individually with females, but not when pair members conjointly encountered females. In Experiment 3, males were paired for several weeks before encountering females. In cases in which home cage dominance was constant, the more aggressive males ejaculated more frequently both when tested individually and when tested as pairs.