Sexual Harassment And Mating Competition In Tibetan Macaques(Macaca Thibetana)

Most of primate animals live in muliti-male and muliti-female societies,formation of these groups benefits from cooperative forging and collective defense,However,individuals in groups also suffer competitions from food,space,and sexual partner.Mating competition is always an interesting topic in behavioral research.In multi-male and muti-female societies,sexual harassment is defined as any form of mild harassment that group members direct toward a copulating pair(mating male/mating female),it can influence an ongoing copulation.Theoretically,it is argued to be a strategy increasing harassers' sexual competitiveness in future by decreasing mating success of copulatory individuals.In this study,we analyzed the variation in patterns and distribution of harassment in Tibetan macaques(Macaca thibetana)of YA1 group at Mt.Huangshan,China from August 2016 to May 2017 in the context of sexual competition.The following main results:(1)The adult male performed more sexual harassment in Tibetan macaques(48%),and most sexual imterruption(43/50,86%)were initiated by higher-ranking males directed toward subordinate males;(2)The non-contact patterns of sexual harassment were higher than contact pattern(P<0.05),The non-contact patterns of sexual harassment by adult males were higher than contact pattern(P<0.05).adult female showed more non-contact harassment than contact harassment(P<0.05);(3)The results showe d that adult males performed harassment during mating season more than in non-mating season(P<0.05),There is no significant difference in the rate of sexual harassment by adult female between mating season and non-mating season(P>0.05);(4)Adult male harassers performed more harassment directed toward mating male than to mating female(P<0.05),adult female harassers performed more harassment directed toward mating male than to mating female(P<0.05);(5)There is no correlation between sexual harassment and social relations(eigenvector centrality:P>0.05,Composite Sociality Index:P>0.05),but there is a positive correlation between sexual harassment and social relations(eigenvector centrality:P<0.05,Composite Sociality Index:P<0.05);(6)The adult female harassed kin individual more than to non-kin individual(P<0.05).The harassment by adolescent was more frequent to non-kin individuals than to kin indi,viduals(P<0.05),juvenile individual harasser more copulation of kin than non-k:in individual(P<0.05);(7)Duration of mating with sexual harassment by adult males was shorter than the matling without harassment(P<0.05).On the cthere ontrary,harassment by adult female often increased duration of mating(P<0.05),is no difference on duration in sexual harassment by male and females(P<0.05);To sum up,there are differences in sexual harassment in Tibetan macaques.Sexual harassment by adult males may be explained by sexual competition hypothesis.On the contrary,there is no correlation between sexual harassment by adult female and mating competition.We suggest that sexual harassment is one form of sexual competition and can be a mechanism to influence copulatory behaviors by decreasing copulation's duratjion.Our study provides new evidence to further explore the function of sexual harassment within the framework of sexual competition,and it also supports us to understand the motivation of sexual harassment in different age-sex classs,and it provides scientific basis for deeper understanding of social animal mating competition and adaptive difference.