Wehrenberg W B, Dyrenfurth I
J Reprod Fertil. 1983 May;68(1):119-22. doi: 10.1530/jrf.0.0680119.
Macaques (Macaca mulatta and M. assamensis) which had been maintained on a 12L :12D light cycle for the previous 4 years and had 25-35-day menstrual cycles were randomly assigned to two groups. Those in Group 1 were kept in 12L :12D for 13 months. Those in Group 2 were subjected to three successive 5-month periods of 20L :4D, 4L :20D and 20L :4D. There were no significant differences between the two groups in the frequency, duration and percentage of ovulatory menstrual cycles, suggesting that photoperiod is not the sole regulator of seasonal breeding in these animals.
在过去4年中一直处于12小时光照：12小时黑暗光周期且月经周期为25 - 35天的猕猴（恒河猴和阿萨姆猕猴）被随机分为两组。第1组猕猴在12小时光照：12小时黑暗条件下饲养13个月。第2组猕猴经历了三个连续的5个月周期，分别为20小时光照：4小时黑暗、4小时光照：20小时黑暗和20小时光照：4小时黑暗。两组在排卵性月经周期的频率、持续时间和百分比方面没有显著差异，这表明光周期并非这些动物季节性繁殖的唯一调节因素。
