Food Competition And Resource Distribute Mechanism Of Rhinopithecus Roxellana In Qinling Mountains

A special habitat is composed of multiple food patches with different resource qualities in addition to other factors.Choosing the best food patches with the greatest benefits for animals is an optimal choice increasing their own fitness,and the impacts from different competition models and intensity for the patches also affect their choices Among the primates,different types of social structure makes individuals have no random chances,and equal social status in approaching the patches,which leads to unequal distribution of the food resources within society or groups.Golden snub-nosed monkey?Rhinopithecus roxellana?studied in this study is featured by a unique social structure with hierarchical components,including breeding groups showing obvious social hierarchy between units.As such in the case of limited food resources,competition appears and gets intensified,which leads to the differentiation of social relationship among individuals,and uneven resource allocation in the society.This has profound impacts on community structure.Unfortunately,such relationship,competition and impact are still less understood,and it is necessary to carry out further analysis to understand some of the mechanisms.It has been reported that the ideal free and despotic distribution models are usually important theoretical means to explain the influence of food resource patch quality on individual spatial distribution.As for food competition,the behaviors of how individual using temporal and spatial relationship between different food patches can be used to analyze the relationship between individual and the society;explore the origin of internal individual social differentiation within the community;understand distribution patterns of food patches for different community classes,and individual relationship with the community;and analyze the influence on the changes of social structure.An ideal free distribution model suggests that animals disperse in several resource patches,and number of the animals in different patches is proportional to the quality of patches.An ideal despotic distribution model proposes that individuals or groups with high grades in the community occupy high-quality resource patches,while those with low grades are forced to feed within the patches not used by high-grade groups.According to social structure type of the golden snub-nosed monkeys,we propose an ideal free distribution model for them should include:1).number of the individuals feeding in each patch is proportional to the quality of available resources in each patch;2).When food is evenly distributed,individual of OMU is evenly distributed in each patch.3).High rank OMU monopolizes high quality patches.In summer and winter,under the conditions of different natural food supply conditions,we use artificial feeding methods to simulate food patches,and verify the above two hypotheses in order to answer the different competitions and food distribution within the above-mentioned communities.We carried out this study from December 2017 to June 2018 on a group of the golden snub-nosed monkeys in Huangbaiyuan National Nature Reserve,based on a provisioned distribution of food patches in natural habitats.We designed two provision types:the first one is a non-equal ratio feeding type,in which feeding food in a food mass ratio is 6:3:1 for three circular food patches with the same size;and the second one is an equal ratio feeding type,in which feeding food in a food mass ratio is 1:1:1 in three circular food patches with the same size.During the experiment,video cameras continuously recorded feeding behavior,and spatial distribution of all individuals in the patches.The following results indicate:1.Regarding non-equal feeding type,there is no significant number difference between the individuals feeding in different food patches in winter or summer and those predicted by ideal free-distribution type?winter:?²=0.61,df=2,P>0.05;summer:?²=0.162,df=2,P>0.05?,in winter and summer.As for the equal feeding type,a significant number difference between the individuals feeding in each plaque and those predicted by the ideal free distribution type was not found?winter:?²=0.182,df=2,P>0.05;summer:?²=0.372,df=2,P>0.05?,indicating that individuals feeding in food patches and the distribution of monkeys fit to the assumption of ideal free distribution model.2.In the case of same feeding patches,OMUs showed significant difference in occupation of only a single food patch in winter(F_?2,42?=3.23,df=2,P=0.049);High-rank OMU occupy larger food patch area,and medium-and low-rank OMUs use less patch area than the high-rank OMU,which is inconsistent with Hypothesis 2;in summer,similar to winter,in summer highs OMU occupies more food patch area than winter,while medium and low rank OMUs take up less food plaque area,but high grade OMU occupies a larger area than winter There are significant differences in utilization of two food patches in summer(F_?2,42?=3.382,df=2,P=0.043;F_?2,42?=8.428,df=2,P=0.001),which is inconsistent with Hypothesis 2.The results indicate that individuals in OMU and other individuals within OMU compete for food plaques to feed on one food plaque as much as possible,but there are still members competing in other patches,which are OMU rank that cannot be shaded by each member,and winter Food competition between OMUs is more intense than in summer.3.Feeding frequency of different OMU in patches with high food quality is significantly different[(winter:F_?2,42?=9.112,df=2,P=0.001;and summer:F_?2,42?=15.83,df=2,P<0.001)].With regard medium grade OMU,however,a significant difference in the feeding frequency was not identified in winter,but in summer[(winter:F_?2,42?=1.771,df=2,P=0.183;.summer:F_?2,42?=6.252,df=2,P=0.004)].As for low-quality food patch,there is no significant number difference in feeding frequency among OMUs in both summer and winter[(winter:F_?2,42?=0.004,df=2,P=0.996);summer,F_?2,42?=1.771,df=2,P=0.183)].This result is in line with Hypothesis 3.However,this result further proves that in the season of food shortage and competition,high-rank OMU has an absolute advantage for patch,giving priority to high-quality food patches,while medium-rank OMUs choose to use medium-quality Food patches,low-rank OMUs occupy more of low-quality food patches and occupy less of high-quality food patches.This study,thus,indicates that quantity distribution of the golden snub-nosed monkeys in food patches fit to ideal free distribution model,while the occupation frequency of food patches fit to ideal despotic distribution model.Individual food resource distribute patterns are subject to seasonal availability,and unit level effects.The significance of this study is to reveal distribute mechanism of food resource at the basic unit level in the primates with Multi-level social structure.