Qinling Golden Monkey (rhinopithecus Roxellana) Mating Behavior

This study, based on 656 hours of focal observations, aimed to describe the sexual behavior of the wild Sichuan snub-nosed monkey {Rhinopithecus roxellana) and compare the results with previous studies on captive populations. Results found that copulation was usually initiated by female courtship, this was followed by pelvis thrust in a dorso-ventral posture, performed on the ground (83.54%), in a tree (11.89%) or on a cliff (4.57%) and continued for 15.96±0.41s. Of the 328 episodes of behaviour after copulation observed in our study, females moved unhurriedly from the male or stayed close to him 106 times (32.32%), exhibited a "copulatory dart" (i.e. the female darted several meters away from them and sat down) 91 times (27.74%), actively groomed the male 89 times (27.13%), and hugged the male 15 times (4.57%).The doubt-clasp gesture during copulation was observed in this study for the first time, this gesture was not reported in previous studies carried out on captive populations. Copulation was shown to occur at almost any stage throughout the breeding and birthing seasons, including up to a few days before parturition. Sexual interference was also observed, which we suggests supports the "sexual-competition hypothesis" i.e. the harassers reduce the mating success of copulating animals or attempt to gain future copulations at the expense of one of the mating individuals. Additionally, I observed two ways in which juveniles learnt sexual behaviour, firstly through observations of adult copulation process, and secondly through prostrating or mounting peers as a form of social play.Copulations with extra-group males are clearly important at an evolutionary level if they result in conceptions, but there can also be other, more indirect benefits involved. Extragroup sexual behavior has been reported in both monogamous primates and polygynous primates. In this paper, the extra-unit sexual behavior of Sichuan snub-nosed monkey (Rhinopithecus roxellana) was firstly studied in their natural habitat. We observed 12 times of extra-unit copulation during our observation from November 2001 to December 2003 intermittently. During my observation, the number of units within the group fluctuated from six to nine. Sampling of the sexual behavior was performed using the methodology described by Martin & Bateson (1993). Besides the extra-unit sexual behavior occurs rarely all the year and it is more frequent at the mating season than at non-mating season. The sponsor in the behavior is almost adult and subadult female. As for the monkey, the strategy of copulating with neighboring units' male appears to support the "heterozygosity hypothesis" that females choose genetically dissimilar partners to increase the degree of heterozygosity in their offspring. Sexual behavior data was collected using focal animal sampling and a total of 733 hours of observations were recorded between March 2003 and May 2004. During this period a total of 399 copulations including 22 multiple copulations were observed. I found that the mean duration of female multiple copulations per hour were greater in themating season (19.67 ± 1.29s) than in the non-mating season (9.8 ± 2.46s) and the number of female multiple copulations per hour ranged between two and five. During the mating season both adult and sub-adult females were the main initiator of multiple copulations whereas during the non-mating season males become the primary initiator. This study has also shown that female multiple copulations occur within both the mating and the non-mating season suggesting that the purpose of this behavior is not limited to propagation. Males may use multiple copulation behavior in order to establish or cement reproductive relationships.Data was collected on the socio-sexual behavior of a free-ranging group of Sichuan snub-nosed monkeys (Rhinopithecus roxellana) in the Qinling Mountains. Mounting behavior was observed to follow male-male inter-unit conflicts in both parties. This pattern was documented across both mating and non-mating seasons. Females' proximity to males would increase during the conflict. Intromission was rare during post inter-unit conflict mountings. The benefits of such a strategy are discussed in terms of anxiety reduction and female reproduction.