Kinship Promotes Affiliative Behaviors And Affects The Transaction Of Biological Market In Female Golden Snub-Nosed Monkey(Rhinopithecus Roxellana)

In social mammals,kinship is an important factor that often affects the interactions among individuals within groups.In primates that live in multilevel societies,kinship may affect affiliative patterns between individuals at different scales within the larger group.In golden snub-nosed monkey,it has been confirmed that the adult females in a one-male unit(OMU)are either relatives or nonrelatives,and that a biological market exists(with grooming as the general “currency”).In this study we use field observations and molecular methods to reveal(i)how kinship affects affiliative behaviors between adult females,and(ii)the influence factors of the “price” in biological market.Relation between kinship and affiliative behaviorsData was collected from 21 adult females in 4 OMUs.The composition of these 4 OMUs were stable during the observation period,and adult female dispersal was not observed.Because few affiliative behaviors were observed between individuals from different OMUs,we excluded such behaviors in subsequent analyses.Genetic samples were collected from target individuals,and pairwise relatedness between adult females was estimated from microsatellite genotypes that obtained from 19 microsatellites.A total of 877 grooming events,2127 proximity events and 431 approach events was observed and recorded during this study.Pairwise relatedness and proximity index(PI)for three types of affiliative behaviors(continuous grooming time,proximity frequency,and approach frequency)of 49 female-female dyads were calculated.Correlation analysis was performed between kinship and affiliative behaviors(grooming,proximity,approach).We develop a novel nonparametric test,the partition Mantel test,to measure independently the correlation between kinship and each of three affiliative behaviors.Our results show that more closely related females are more likely to groom each other.Average relatedness between adult females within the same OMU is higher than that between adult females from different OMUs.We suggest that closely related females may reside in the same OMU,and that kinship plays an important role in maintaining the social structure of this species.Factors of “price” in biological marketData was collected from 25 adult females in 5 OMUs including grooming,feeding order,and non-mother infant handling.The composition of these 5 units were also stable during the observation period,without adult member dispersal between units.A total of 1344 grooming events,243 infant handling,and 305 feeding movements was observed and recorded during the study.Correlation analysis was performed between potential factors including grooming time difference,hierarchical index difference,and pairwise relatedness,while the “goods”,infant handling,is used as the dependent matrix in partition Mantel test.Hierarchical index is estimated by feeding order.Relatedness matrix was constructed from pairwise relatedness between 25 females.The infant handling time,hierarchical index difference and grooming time difference was normalized within unit to eliminate the influence of unit size.Thereafter,these factors were used to construct matrices in partition Mantel test.The results show that grooming or kinship have a significant correlation to infant handling.Hierarchical index difference have no significant correlation to infant handling.The grooming,relatedness,and hierarchy explained 16.9% variances of infant handling,grooming time difference is the most influence factor of infant handling,and their contribution rates are 13.4%,2.5% and 1.7%,respectively.Biological market and kinship both shape the formation and behavior of Qinling Mountains golden snub-nosed monkey societies.“currency”(grooming)and “discount”(kinship)plays a major role and a minor role,respectively,in the trading of “goods”(infant handling).