Social Behaviors Of A Provisioned Group Of Sichuan Snub-nosed Monkeys (Rhinopithecus Roxellana) In Shennongjia Nature Reserve

To describe the function of social behavior in maintaining group structure of Sichuan Snub-nosed monkeys(Rhinopithecus roxellana),evaluate the effects of provisioning on social behavior,reveal the mechanism of social structure formation,the effects of nursing behavior on infant survival rate,how to avoid inbreeding,this paper aimed to study the aggressive behavior, affiliative behavior,mating behavior and nursing behavior of Sichuan Snub-nosed monkeys,in Dalongtan research center in Shennongjia National Nature Reserve(110°18'E,31°29'N) from 2007 to 2008.Using behavior sampling and all-occurrence recording methods,the differences between sexes,among ages,within OMU and between OMUs,reproducing and non-reproducing seasons for aggressive and affiliative behavior were compared.The function of female multiple prostrating behavior,extra-unit prostrating behavior and the interfering behavior were discussed. The occurrence frequencies of nursing behavior were compared,the correlation between the month age of the infant and the number of nursing behavior were tested.The main results were listed as follows.(1) The recipients did not exhibit significant differences among sex/age classes,while significant differences in sex/age classes were observed in initiators for aggressive behavior. Males initiated aggressive behaviors more frequently than females.The occurrence frequency of aggressive behaviors among age classes of initiators were:adults>the young>juveniles> sub-adults in OMUs and adults>sub-adults>juveniles>the young in the AMU.The initiators worked in concert with recipients in age class,that is,those initiating more aggressive behaviors received more aggressive behaviors.(2) More aggressive behaviors occurred within each OMU than among OMUs during feeding process,this may because food items be given to each unit.There were observed differences in the occurrence frequency of aggressive behaviors between reproducing and non-reproducing seasons,more aggressive behaviors occurred in non-reproducing seasons than those in reproducing seasons,reproduction could reduce the aggressive behavior.(3) There were no significant differences in affiliative behaviors between sexes both for initiators and recipients,so sex was not a main factor affecting affiliative behavior.But it varied significantly among age classes in the OMU(in descending order):adults,juveniles,the young, and sub-adults;while within the AMU,the frequency order was adults,juveniles,sub-adults,and the young,so adults and juveniles exhibited more affiliative behaviors than those exhibited by sub-adults and the young.(4) Individuals within OMU exhibited more affiliative behaviors than those between OMUs, this result indicate that members in OMUs are closer to each other than individuals between OMUs be.There were no observed differences in the occurrence frequency of affiliative behaviors between reproducing and non-reproducing season,reproduction did not affect affiliative behavior.(5) Among the recorded 241 prostrating behaviors,females initiated 205 times,the percentage was 85.06%;males initiated 36 times,the percentage was 14.94%.The percentage of successful prostrating in males was 58.33%,which in females was 65.85%.The percentage of successful mating was 37.96%.Females were the main initiators,most prostrating behaviors were successful,no matter the initiators were males or females.(6) There were interfering behaviors from other adult females during the mating process,and all these behaviors occurred in mating season,this supported the hypothesis of "sexual competition".Those interfering behaviors from juveniles were no effect,only reflected the growth process of juvenile sexual behavior.(7) There were a few extra-unit prostrating behaviors,to some extent,this supported the hypothesis of "heterozygosity".There was contradiction between males and females,females initiated actively,but males tried their best to prohibit this behavior.(8) Mothers usually cared for infants by carrying and embracing,there was significant negative correlation between month age of infants and the number of maternal-infant behaviors.The maternal-infant behaviors could guarantee infant survival rate.(9) There was no observed negative correlation between month age of infants and the number of paternal-infant behaviors,this indicated that month age of infants did not affect the number of paternal-infant behaviors.This paternal-infant relationship was between admit type and occasional admit type of animal paternal-infant relationships.(10) Aunts usually cared for infants by embracing and kidnapping,there was significant negative correlation between month age of infants and the number of aunt behaviors.Aunt behavior could guarantee mothers enough time to feed and provide infants with enough milk.