The Study Of Unit Development And Evolvement In Golden Snub-nosed Monkey

The multilevel society of golden snub-nosed monkey comprised of two basic bands, breeding band and all-male band, whereas breeding band composed of several polygamic units (one male units, OMUs). We found that there are still have some difference among OMUs, some OMUs are usually feed, travel and rest on the brink position of provisioning site, they could not occupy a beneficial position and obtain more food resource, whose easily and frequently get attack from other units, we named these units as "peripheral unit". Relatively, "core unit" could dominate more advantageous position and food resource, individual transfer (including adult male disperse) occurred rarely. Explore the evolvement process of peripheral unit to core unit and reveal which factors impact the unit development will facilitate the understanding regarding the population stable mechanism of gold snub-nosed monkeys (Rhinopithecus roxellana).From October 2014 to June 2015, we adopt the focal animal sampling, continuous recording and instantaneous scanning method to observe and record the behavior data (grooming, embracing and fighting) and spatial foraging sequence in dietary event for a provisioning R.roxellana band living in Zhouzhi National Nature Reserve, Qinling mountians. In the study period, we totally recorded 14 OMUs'foraging sequence in 50 days. Behavior data were recorded for eight OMUs in spring and summer, and six OMUs in autumn and winter, separately, then collected feces and hair samples on the basis of identifying focal individual. We calculated relative coefficient of each individual based on 21 high polymorphism microsatellite loci information. The results showed that all OMUs could be clearly categorized two classes from feeding event, peripheral units and core units; core unit contain more adult females than peripheral units, core units could predominately feeding together and share foods; conflict behavior occurred between two classes are more than it happened within class, peripheral units are susceptible to attack by core units. Hierarchy among each OMUs are responsible for the such category difference and cooperation; frequency of female allied attack in core unit is more than peripheral unit(t=-10.968, df= 37.369, P= 0.000); Kinship among individual is more intimate in core unit than peripheral unit(t=-3.594, df= 49, P= 0.001). Therefore, female alliance and kinship are main factors that improve units' cohesion and facilitate peripheral unit developing into core unit, furthermore, close female kinship and high rank among all adult females within unit significantly impact the female co-investment for their alliance. The results show that whether from within the unit between individuals or units have a similar goal of evolution, and possess more resources in order to improve their fitness, thus kinship and hierarchy has a significant importance in unit development and succession.