22-KHZ PRE-EJACULATORY VOCALIZATIONS OF THE MALE-RAT

Male rats were found to emit 22-kHz pre-ejaculatory vocalizations when approaching females after they had achieved 4 or more ejaculations. The onset of these vocalizations was associated with increases in mounts without intromissions and decreases in intromission rate. On those ejaculatory series with 22-kHz pre-ejaculatory vocalizations, the females showed a lower lordosis intensity and a higher number of agonistic responses than on series with no vocalizations. It is suggested that the pre-ejaculatory vocalizations may serve to inhibit female agonistic behavior and stimulate sexual responsiveness. © 1979.