Study On Dominance Hierarchy Of Sichuan Snub-nosed Monkeys (Rhinopithecus Roxellana) In Qinling Mountains

Data on social structure and sex ratio of a herd of Sichuan snub-nosed monkey were collected in Zhouzhi National Reserve, which lies in the north slope of the Qinling Mountains from July 2002 to June 2003. By the use of Ad libitum Sampling and focal sampling methods the group in the west Ridge was studied. The results revealed that the whole group was composed of both lots of one-male-units and all-male-unit. One-male-units shows there are 8 one-male-units, each of which on average is made up of one adult male, 3.75 adult female, 1.13 sub-adult female and 3.75 Juvenile, and additional 1.5 infants in breeding season. Marriage should belong to harem above promiscuity. Through analyzing the sex-aged and sex ratio respectively, results showed that male individuals would leave from their one-male-units gradually during the courses of growth, especially in 3 years old and there are no male individuals at the age of about 4 years. This revealed that one-male-units were matrilineal societies, that is to say, female individuals have been in birth-group all ones life. In order not to inbreed, each male of one-male-units often come out of all-males-unit or other one-male-units. Adult females in wild field incline to reproduce every other year by comparison of the west herd's reproduction in the successive two years. Because of Adult females'age-difference, adult females in each of one-male-units breed differently.If the group was consisted of same kind of animals, dominance hierarchy was reported among individuals. By the use of Ad libitum Sampling data on the direction and number of aggressive behavior and submissive behavior in the west group of Sichuan snob-nosed monkey was collected from July to December 2002 and April to June 2003. The phase of September to December is called the mating season and that of April to June is named the birth season.and dominance index analyzing data of aggressive behavior and submissive behavior showed that dominance hierarchy among eight units is a linear dominance ranking order. As to mating season the ranking order was: Heitou>Changmao >Jingzitou>Toutu>Duanzhi>Bazitou>Daoba>Hongtui; In birth season, Heitou > Changmao > Toutu > Bazitou > Jingzitou > Duanzhi > Daoba > Hongtui and in the whole year, Heitou > Changmao> Jingzitou>Toutu> Bazitou > Duanzhi> Daoba > Hongtui, which shown that the rank order between the highestdominant families such as Heitou and Changmao, and the lowest subordinate families such as Daoba and Hongtui had not changed, and changed among Toutu , Bazitou, Jingzitou and Duanzhi mainly in birth season. The unchanging reasons are that the higher dominant families's individuals hold together tighter than those of the lower subordinate families and in birth season the variational cause was that the extent of solidarity among families's individuals changed relaxation and the dominant had nothing to do with families's quantity and their adult male. Eight families in the west group often collide with each other and conflict usually ends by subordinate avoiding. There is no monkey-king in the west group. Although Heitou unit's dominance index is the highest, its unit does not play a king role, and individual's dominance is revealed by unit's dominance.Subsequently, Ad libitum Sampling was used to record aggressive behavior and submissive behavior in each one-male-unit. Dominance index analysis showed that a linear dominance ranking order exists in each one-male-unit. In mating season a linear dominance ranking order was: Heitou>Yuanlian >Xiaoke>Yizuomao>Dabangchui; Changmao > Baixian > Heiwei > Tiemao > Qianqian > Heifeng > Shuangxuan > Baitou> Xiaobai; Bazitou > Jingu > Beitou > Xiangchang > Erxuan > Hongtoupa > Naizui > Youque; Jingzitou > Liuliu > Kuanbanhou > Zaibanhou > Jiguan > Duanwei > Xiaoheiwei > Jidan; Tutou > Hongguan > Banheixian > Huangguan > Shuanghang > Heixian > Huangding > Balding; Duanzhi > Heituo > Zhazhahong > Guitou > Hongtuo >Zhazhahei; Daoba>Baibei>Faqia>Aoxian>Pingtou>Wuming>Nailao; Hongtui >Shuangliu>Wanmao>Heibei>Sikong. In the birth season,...