Social Cognition And Rank-related Benefit Of Golden Snub-nosed Monkeys

Dominance rank is a common resource-regulating mechanism in group-living animals,influencing the proportion of advantageous resource possessions among individuals,and leading to individual differences in resource priority;Social cognition is an ability of sicial animal to adapt to the complex and changeable environment,and to understand themselves,others and society.They are helpful to promote the intelligent distribution of advantage resources,to improve the survival adaptability of the individual,and enhance the social organization of the group.We examined which behavior strategy and cognitive strategy would be adopted to maximize benefits.But so far,the researches on dominance rand and rank-related benefit mechanisms,and how to recognize the social rank and resource possession in Golden snub-nosed monkey have not yet been carried out.By attracting monkeys via feeding,we would observe individuals closely.Based on individual identification and hierarchical relationships,we selected six one-male units(OMUs)of provisioned Golden snub-nosed monkeys as targets.By collecting data on some motivational behavioral(such as yield,aggression support,mating grooming),signal,facial expression,and the social behaviors differences before and after the rank change and copulatin,resource possession,and on extent of competition behavior on advantageous resources,we examined the cognitive behavioral characteristics of female rank-related benefits,dominance rank,resource possession and the co-variation relationship of social behaviors,at the Dapingyu scenic spot in the Guanyinshan Nature Reserve on the south slope of Qinling Mountains,China.The research would address problems associated with theory of natural selection about the evolution of primates regarding the social cognition,explore the relationship between social phenomenon and individual psychology,the rate of rank-related benefits and the types of individuals involved.The findings would also contribute to more in-depth understanding of resource allocation strategies and the cognitive behavioral strategies,as well as the development and improvement of social organization and cognitive psychology.Our major results are:1.We evaluated dominant rank of female in OMU of provisioned golden monkey,by defending dominant spatial position.Our found that compared with dominance index of displacement,the dominance index of defending dominant resources is feasible and easier in operation and statistic,which can determine female ranks in short term and may facilitate the study of individual ranks in non-human primates under captivity and provisioning conditions of nature.2.Using instantaneous scan and focal animal sampling to collect data on spatial position and reproductive behavior to clarify the mating period and analyze differences before and after fertilization.We confirmed significant differences in the rates of sexual solicitation success and found that the rate before fertilization was significantly higher than that after fertilization.Results also demonstrated significant positive correlations between rank status and the rate of solicitation success and time of fertilization,which were found to be significantly higher and earlier,respectively,in higher-ranked females than in lower-ranked females.This study revealed that males were able to recognize the pregnancy status and rank of females within their OMUs,which affected their own social and reproductive behavior.3.Using the photo guide experiment,observing and recording the behavior of different age groups.The results showed that gazing behavior in Qinling monkey was exsited,and the patterns of this behavior was differences in different age groups,suggesting that gazing behavior is a development behavior that may be occur in the early primates.This research method can provide reference for the behavior measurement and diagnosis of children with different growth environment.4.We tested whether golden snub-nosed monkeys(Rhinopithecus roxellana)can discriminate facial expressions in different contexts,and how they respond to these facial expressions.Results showed that adult monkeys approached,touched,and looked at affiliative expression stimuli,but avoided agonistic expression stimuli.No significant differences were found in approaching,touching,or looking between the affiliative and neutral expression stimuli.Furthermore,non-adult individuals spent more time looking at the photographs,although no significant differences were found in their responses to different facial expression stimuli.These results indicate that R.roxellana adults can spontaneously discriminate between affiliative and agonistic facial expressions,to which they show different behavioral responses.Thus,adult golden snub-nosed monkeys likely gain important information from the facial expressions of others in order to adjust their potential social interactions.5.We investigated the relationships between female rank and sexual interference and allomaternal behavior in a multi-level troop of this species inhabiting the Qinling Mountains of China.The initiation frequency and success rate of allomaternal snatching by higher-ranked females were significantly higher than that by lower-ranked females.Furthermore,sexual interference by higher-ranked females was significantly different to that of lower-ranked females,although no obvious correlations were found between initiation frequency of sexual interference and female rank.Thus,females appeared to use the information presented in sexual interference and allomaternal behaviors during social interactions to adjust their own behaviors and that of others and to predict how social interactions might progress,indicating that rank cognition among females reduced the potential for conflict and increased social stability in Golden snub-nosed monkeys.