Correlates Of Self-directed Behaviors In Golden Snub-nosed Monkeys(Rhinopithecus Roxellana)

In stressful situations,nonhuman primates frequently display behaviors that are unrelatable to the current contexts and consist of different body care activities,including scratching,self-grooming,body shaking,and yawning.These behaviors are referred to as “self-directed behavior” in ethological literature.More recent data suggest that,at least in nonhuman primates,self-directed behavior may also reflect an emotional state of anxiety.The self-directed behavior data of 22 semi-free-ranging individuals of golden snub-nosed monkeys(Rhinopithecus roxellana)in Guanyinshan National Nature Reserve,Qinling Mountains of China,were collected during the course of July 2014-September 2015 through focal and behavior sampling methods,continuous and instantaneous recording methods.This study aimed to explore the patterns of behaviors of the focused individuals: 1)the correlation of rank and self-directed behavior in females;2)the influence of grooming on self-directed behavior in females;3)the performance of self-directed behaviors in post-conflict observations;4)asymmetries of self-directed behaviors.As the results showed: 1)the self-directed behavior of females was significantly correlated with dominance rank(Rs =-0.721,n =18,p =0.001).The number of close-range individuals within 5m did not affect SDB frequency(p >0.05).The SDB frequency of the target individual was significantly higher when the nearest individual was in with a higher level of dominance within 5m than when the neighbor was a subordinate(t =27.5,n =10,p =0.037),or when there were no other individuals within 5m(t =52.5,n =14,p =0.006).The SDB frequency was also higher in the case of no individual within 5m than the neighbor was a subordinate individual,but not significantly different(t =52.5,n =14,p =0.14).The rank distance was significantly correlated with individual SDB frequency(Rs =0.511,n =56,p<0.001).2)The occurrence of SDB frequency was higher in post-grooming sessions(PG)than matched-control sessions(MC)for donor,but not significant enough(n =141,t =70.52,p=0.07).Compared with the MC,the SDB frequency of the recipient was significantly different(n =141,t =70.36,p =0.046).There was no significant correlation between grooming duration and SDB frequency,either for the donor(n =141,p =0.097)or the recipient(n =141,p =0.057).3)Post-conflict SDB rates with no reconciliation were significantly more than MC(n =18,Z=-2.81,p =0.005)and after reconciliation(Z =-3.296,p =0.001).The SDB rates before reconciliation were significantly more than MC(Z =-1.961,p =0.05)and after reconciliation(Z =-2.118,p =0.034).Post-conflict SDB rates were significant more than MC for the unilateral aggressors(Z =-2.803,p =0.005),unilateral victims(Z =-2.497,p =0.013)and bilateral opponents(Z =-2.191,p =0.028).4)There was laterality on the individual level,but not on group level for scratch(t =0.047,p=0.963),but the intensity of preference is high(t =5.347,p <0.001).There is a significant preference for left side scratching(t =-2.193,p =0.040),and preference intensity was high(t =4.834,p <0.001).The post-conflict scratch was laterality on group level(t =-2.008,p=0.058),and preference intensity was high(t =8.336,p <0.001).There was a significant bias for scratching on the left side of the body during post-conflict periods(t =-2.541,p =0.019),and preference intensity was high(t =6.203,p <0.001).This study showed that the self-directed behavior of golden snub-nosed monkeys was correlated with anxiety.The changes of individual anxiety after grooming and conflict were compared.The hand preference of scratching and the laterality of body position of scratching were discussed.This study verified the feasibility of self-directed behavior as an indicator of stress.This study is expected to provide a reference for future non-human primate emotional research through different research directions.