Seasonal variation in fecal testosterone levels in free-ranging male Japanese macaques |
| |
Authors: | Muroyama Yasuyuki Shimizu Keiko Sugiura Hideki |
| |
Institution: | Department of Ecology and Social Behavior, Primate Research Institute, Kyoto University, Aichi, Japan. ymuro@pri.kyoto-u.ac.jp |
| |
Abstract: | Seasonal variation in fecal testosterone levels in free-ranging male Japanese macaques (Macaca fuscata) was examined with reference to their dominance rank and age class. Six adult (>or=7 years old, three higher-ranking and three lower-ranking) and four adolescent (5-6 years old, two higher-ranking and two lower-ranking) males were selected as target animals. Fecal samples of these males were collected during the first 3-5 days of each month and analyzed by the method developed by Barrett et al. Primates 43:29-39, 2002 b]. Testosterone levels varied significantly across the 12 months, and were highest in the early and middle parts of the mating season (i.e., October and November). Higher-ranking adult males displayed a peak testosterone level in October, whereas lower-ranking adults had no clear peak in the mating season. Such a difference in testosterone peaks in males could provide higher-ranking males more opportunities to fertilize females at first ovulation in the mating season than lower-ranking males. |
| |
Keywords: | testosterone feces seasonality Macaca fuscata age class dominance rank |
本文献已被 PubMed 等数据库收录! |
|