Study On Manual Laterality Among Age And Sex And The Response To Novel Object Of Golden Monkeys(Rhinopithecus Roxellana) In The Qinling Mountains

Manual laterality is a behavioral expression on the struture and function of human cerebral cortex and a hallmark of behavior on hemispheric specialization. Studies on hand preference of non-human primates can help us to understand the evolution and origin of cerebral hemisphere in human. In this study, I aimed to study the effects of age and sex on laterality of76semi-free-ranging group of Golden monkeys (Rhinopithecus roxellana) in Zhouzhi National Nature Reserve, Qinling Mountains of China during four spontaneous actions (Unimanual feeding, Manual feeding, Unimanual grooming, Manual grooming) and one experimental action (The tube task). I found that1) the group-level left-handedness was found in unimanual feeding, manual feeding, manual grooming and the tube task.;2) sex didn’t effect the hand preference in all actions;3) age affect the direction of hand preference significantly in unimanual feeding and manual grooming, and affect the strengthen of hand preference significantly in unimanual feeding and the tube task.. Bimanual feeding action and the tube task were firstly used to investigate the manual laterality in golden monkeys, which make a breakthrough of limits of behavioral actions in the studies of the same species, and the finding further confirmed the "tast-complexity" model that that strong preferences and group-level biases of manual laterality would be more likely to appear in complex tasks.When facing novelty, animals may display neophilic and/or neophobic behaviors. The neophobic behavior is the avoidance or caution toward unknown stimuli, but the neophilic behavior is the exploration toward them. The Golden snub-nosed monkey (Rhinopithecus roxellana) is an arboreal Old World monkey species and has never been studied in responsiveness toward a novel stimulus. The study connected a novel object with a familiar food closely. We tried to investigate the responses toward familiar foods in the presence of a novel timulus and the difference of age and sex in Golden snub-nosed monkey. The main results are that:1) the monkeys exhibited neophilia and neophobia simultaneously when facing novel stimuli;2) age affected the response to the novel stimuli significantly, in which immature individuals responded to the novel stimuli were the most frequently and infants were lest frequently;3) there was no significant difference of sex, although females was higher responsive to the novel tube than males. The result supports the "readiness to eat" hypothesis that the presence of the novel object can increase the latencies to explore and eat the familiar food.