Seasonality of matings and births in captive Sichuan golden monkeys (Rhinopithecus roxellana)

This study, based on three years of mating behavior observations and 10 yea rs of birth records, reveals that Sichuan golden monkeys in captivity displ ayed a marked seasonality of mating behavior and births. The peak of mating s occurred around October, and births occurred in March-June. The birth pea k followed the mating peak by six to seven months. This seasonal cycle of m atings and births was similar to observations made in the wild, where both temperature and food resources were favorable in spring. The time delay bet ween peaks of matings and births was the approximate length of gestation, w hich implies that mating behavior was concentrated during the period of con ception. We suggest that the peak of births in captive Sichuan golden monke ys occurred during the time of year with the most favorable environmental c onditions, and the peak of matings corresponded with the period of concepti on. (C) 2000 Wiley-Liss, Inc.