Hayama Shin-ichi, Nakiri Sachie, Konno Fumiharu
Laboratory of Wildlife Medicine, Nippon Veterinary and Life Science University, Musashino, Tokyo 180–8602, Japan.
J Vet Med Sci. 2011 Jun;73(6):809-12. doi: 10.1292/jvms.10-0420. Epub 2011 Jan 11.
This study is the first to determine the conception dates of specific individuals and estimate the pregnancy rate of a wild population in Japanese monkeys. The conception dates estimated from the embryonic ages of 37 fetuses were distributed over 128 days between September 17 and January 23, with a mean conception date of November 19 (SD=29.2 days). A comparison of the mean conception dates among age groups showed a significantly delayed conception in the subadult animals (aged 4 to 5 years; December 5, n=8) than in the adult animals (aged 6 or more years; November 15, n=29; P<0.03). The mean pregnancy rate among animals aged 4 years or more in this local population was estimated to be 48.5% (32/66).
本研究首次确定了特定个体的受孕日期，并估算了日本猕猴野生种群的怀孕率。根据37只胎儿的胚胎年龄估算出的受孕日期分布在9月17日至1月23日的128天内，平均受孕日期为11月19日（标准差=29.2天）。各年龄组平均受孕日期的比较显示，亚成年动物（4至5岁；12月5日，n=8）的受孕时间比成年动物（6岁及以上；11月15日，n=29；P<0.03）显著延迟。该当地种群中4岁及以上动物的平均怀孕率估计为48.5%（32/66）。
