Sexual interference in the golden snub‐nosed monkey (Rhinopithecus roxellana): a test of the sexual competition hypothesis in a polygynous species

Abstract

Sexual interference (SI), which is defined as any disturbance directed to a mating pair by other individuals, has been reported in several primate species. It is widely suggested that successful harassers experience improved mating success by increasing their access to reproductive partners as well as by reducing the mating success of rivals. Although theories of primate sexual conflict highlight male intra-sexual mating competition, females also are reported to actively disrupt copulations between mating partners. In this study, we investigated SI in a multilevel troop of Golden snub-nosed monkeys (Rhinopithecus roxellana) inhabiting the Qinling Mountains, China. Behavioral observations of 11 one-male units (OMU) that comprised the multilevel troop were conducted from September 2007 to May 2008. During this period 17.1% of 652 documented intra-OMU sexual encounters were characterized either by mild or aggressive forms of harassment. Sexual harassment was typically performed by a single individual (91.9%), and in 75.7% of cases the harasser was an adult or sub-adult female. The frequency of female harassment was positively correlated with the number of adult and sub-adult females residing in an OMU, and resulted in a significant decrease in matings ending in ejaculation. We found that the amount of SI a female received was not a significant predictor of her reproductive success. However, females who conceived during the mating season directed higher levels of harassment at other females than females who did not conceive. We evaluate the strength of the sexual competition hypothesis and the hormonally modulated aggression hypothesis in explaining patterns of SI in female Golden snub-nosed monkeys.

Male Dispersal Pattern in Golden Snub-nosed Monkey (Rhinopithecus roxellana) in Qinling Mountains and its Conservation Implication

“…This indicates that the impacts of mating system on dispersal pattern may be affected by other ecological factors. With regard to the golden snub-nosed monkeys, its mating behavior is not limited to resident male of OMU, other resident males and bachelors also have chances to mate with OMU females26273637. As a result, both males and females were found to disperse within herd24.Even though we found some healthy females to leave their natal herd, their dispersal frequency was lower than that reported from a previous study based on genetic method29.…”

Market Powers Predict Reciprocal Grooming in Golden Snub-Nosed Monkeys (Rhinopithecus roxellana)

“…This reproductive strategy, in a sense, weakens competitive interactions between females for access to males and ensures that female relationships are not severely disrupted even if the adult sex ratio decreases in the non-mating season. Even under strong competition, female R. roxellana still possess other behavioral strategies that can be utilized to access the resident male such as female dispersal and sexual interference [38], [49], [74]. Our results suggested that for R. roxellana , such a market may undergo seasonal fluctuations.…”

Age‐ and sex‐based patterns of positional behavior and substrate utilization in the golden snub‐nosed monkey (Rhinopithecus roxellana)

“…Our study band contained over 140 individuals, most of whom were fully habituated to the presence of human observers and have been the focus of behavioral observations for the past 14 years [Qi and Yang, 2011]. Given that this golden snub-nosed monkey band has a home range of almost 20 km 2 and is extremely difficult to follow across steep ravines and mountain terrain, individuals are provisioned with approximately 200 g of corn and radishes per monkey per day over a period of 15 days per month.…”