Chemical and behavioral stimulation from females accelerates recrudescence in male Syrian hamsters exposed to short days.

Interaction with female hamsters maintained under long photoperiods (LP) accelerates behavioral recrudescence in short photoperiod (SP) males. In this experiment, the authors investigated the effects of various types of female sociosexual cues on different measures of reproductive recrudescence in the male. Five groups of SP males were exposed to different female cues for 3 weeks (Weeks 12 to 15). At Week 16, males were allowed to interact with estrus females; behavioral, physiological, and fecundity measures were monitored. The results show that all measures responded in a pseudo-dose-dependent manner to the different female cues presented. SP males not exposed to any female cues and those exposed to distal visual, auditory, and volatile pheromonal cues from estrus females did not copulate, deposit sperm, or impregnate estrus females presented to them at Week 16. SP males allowed direct access to the bedding of estrus females showed marked improvements on these same reproductive measures by Week 16. However, SP males that interacted with LP females between Weeks 12 and 15 showed the greatest level of reproductive function at Week 16. These results show that the type of female sociosexual stimulation is important in accelerating reproductive recrudescence; whereas interaction with LP females may be important in accelerating behavioral recrudescence, both interaction with and exposure to the bedding of LP females may be important in accelerating physiological and reproductive success measures.