Sexual behavior in a captive group of pigtailed monkeys (Macaca nemestrina)

Sixteen pigtailed monkeys (Macaca nemestrina) were studied to determine patterns of estrous cycles and sexual behavior. The average estrous cycle lasted 42 days, the average tumescent period 21 days, and the average quiescent period 17 days. Results are consistent with those obtained from studies of individually caged monkeys. The mean length of gestation for five live births was 174.6 days with a range of 167 to 179 days. Patterns of heterosexual, homosexual, and self-oriented sexual behavior are described and quantified.Mating behaviors of Japanese and pigtailed monkeys were compared. Although individual elements of sexual patterns were similar, there were quantitative differences and differences in the temporal patterning of the behavior.Supported by Grant FR 00166 from the National Institutes of Health, United States Public Health Service.