Male Dominance Rank And Reproductive Success Of Rhinopithecus Roxellana In Qinling Mountain

Social hierarchy is widespread in human and animal societies,The position of individuals in its hierarchy affects their ability to obtain food resources and reproductive resources.In many non-human primates,there is a significant correlation between male rank and reproductive success,but the degree of correlation is influenced by female selection,seasonal reproduction,the number of male competitors,and male reproductive strategies.Under the pressure of competition for reproductive resources,such as seasonal breeding and female selection,it is not clear what strategies the males adopt to obtain reproductive resources for the Qinling golden monkey(Rhinopithecus roxellana)with a multilevel society.To explore the reproductive strategy of males of different rank in the breeding band will provide evidence for revealing the reproductive mechanism,community maintenance mechanism and species evolution mechanism of the population.We analyzed genetic samples and the unit structure information from 2001 to 2017 of the provisioned Golden snub-nosed monkey group in Zhouzhi national nature reserve,Shaanxi province.This paper attempts to study the reproductive strategies of male from two aspects: the number of females and the number of offspring.The results are as follows:1.The males in the breeding band get higher reproductive benefits.The males of the breeding band gave birth to 95.53% of the offspring,and the males of the all-male band gave birth to 5.47% of the offspring.Males of the breeding band have more opportunities to mate with fertile females for higher reproduction gains.This may also be one of the motive factors for the all-male band to follow the breeding band and take the opportunity to replace the male of the breeding band into the breeding band.2.There are more females in dominant units in the breeding band.The number of females in the unit increases as the male ranks higher(Regression analysis: F = 34.350,df = 141,P < 0.01).The number of females in the high-medium rank group is significantly higher than that in the low-rank group(ANOVA:F = 14.231,df = 140,P < 0.01).3.Dominant male in the breeding band gave birth to more offspring and obtain higher reproductive benefits from the unit.There is a significant correlation between male rank and the number of biological offspring(Spearman rank correlation: Rs=0.417,N=40,P<0.01).There are significant differences in the number of biological offspring between the high-medium-low rank group(ANOVA:F = 7.688,df = 29,P < 0.01).The number of biological offspring in the unit of the high rank group is significantly higher than that of the middle rank group(P < 0.01).There is no significant difference in the number of biological offspring in the middle-low rank group(P > 0.05).4.There was no significant difference in the number of offspring outside the unit between the high-medium-low rank group(ANOVA:F = 1.793,df = 29,P > 0.05).This may be one of the motive forces for male to form units and compete for dominance status.5.By analyzing the rank information of the males in the breeding group,this study found that the rank of the males in the breeding group changed in a parabolic pattern during the whole tenure.In summary,this study found that the males of the breeding band gave birth to more offspring,and the males in the all-male band gave birth to fewer offspring.The rank of the males in the breeding group changed in a parabolic pattern during the whole tenure,which is consistent with the growth and development of the individual's body.In other words,with the increase of male tenure in the breeding band,the male rank increases and the number of females in the unit gradually increases.The males with dominant status gain more reproductive benefits by possessing more females by virtue of their own advantages.And the reproductive gains come mainly from within the unit;There is no significant difference between rank in the reproductive gains from outside the unit.This is the motivation for males to form family units and compete for dominance status in a hybrid mating system,and it is also the reproductive strategy for males to improve their own fitness.As the increases of age,the male's physiological function declines and more energy is turned to survival.Finally,the rank of the male declines and leave the breeding band.