Social dynamics of the golden snub‐nosed monkey (Rhinopithecus roxellana): female transfer and one‐male unit succession

Among primates that form multilevel societies, understanding factors and mechanisms associated with the movement of individuals between groups, clans, and one‐male social units offers important insight into primate reproductive and social strategies. In this research we present data based on an 8‐year field study of a multilevel troop of Sichuan snub‐nosed monkeys (Rhinopithecus roxellana) in the Qinling Mountains of China. Our study troop contained 78–126 individuals, and was usually organized into 6–8 one‐male units (OMU). The majority of OMUs were composed of networks of unrelated females and their offspring. We found that 59.7% (43/72) of subadult and adult females in our study troop transferred between OMUs (n=66) or disappeared (n=7) from the troop. In the majority of cases, two or more females transferred together into new OMUs or troops. In R. roxellana, new OMUs formed in several ways. During 2001–2008, 16 adult males appeared in the study troop. Over this period, we observed 13 different males who became harem leaders either by taking over an existing harem or by attracting females from other OMUs into their harem. We also observed four OMUs from a neighboring troop to successfully immigrate into the study troop. The number of individuals in these newly immigrated OMUs was significantly smaller than that number of individuals in resident OMUs. During harem formation, fighting between adult males was rarely observed, and female mate choice appeared to play a crucial role in harem male recruitment and replacement. These results suggest that golden snub‐nosed monkeys are organized in a nonmatrilineal social system. Female mate choice and possibly incest avoidance appear to play important roles in female transfer, male tenure, and OMU stability. Am. J. Primatol. 71:670–679, 2009. © 2009 Wiley‐Liss, Inc.     

秦岭川金丝猴群在非移动时的空间结构

本研究在个体识别的基础上 ,采用瞬时扫描取样法 (Instantaneousandscansampling)和行为的全事件取样法 (Alloccurrencesampling) ,对秦岭川金丝猴 (Rhinopithecusroxellana)的一个投食群的空间结构进行研究。发现秦岭川金丝猴社群的空间结构是以类似于“家庭”的社会单元为基本单位 ,属于同一社会单元的个体主要集中在同一棵树上 (占观察频率的 6 0 6 % ) ,其次是在距离相近的两棵树上 (占 2 9 1% ) ,个体间的直线距离通常保持在 0 - 10m之间 ,主要是在 0 - 5m之间 ,不同的社会单元个体间的空间直线距离主要集中在 10 - 30m之间 ,通常是在 2 0 - 2 5m之间 ,明显大于同一社会单元的个体间的空间直线距离 ,这些研究结果可以作为一种野外鉴别猴群社会单元的尺度 ,供未来的研究人员参考。通过对空间形状近似圆形的猴群进行分层 ,统计表明高社会等级的单元常出现在猴群的内层和中层内侧 (df =1,χ2 =16 6 97,P <0 0 0 5 ) ,中社会等级的单元主要出现在猴群的中层 (df=1,χ2 =2 1 5 4 ,P <0 0 0 5 ) ,而低社会等级的单元出现在猴群的外层 (df =1,χ2 =12 6 0 ,P <0 0 0 5 ) ;等级较高的单元在猴群中占有的空间大小与空间质量也较高 ,随着单元社会等级的降低 ,其占有空间的大小与质量也随之降低 ;变化的     

依据取食优势判断秦岭川金丝猴群OMU的等级地位

2005 年5 月至2006 年5 月,对秦岭北坡周至国家级自然保护区玉皇庙地区一个人工投食川金丝猴群的取食规律进行了研究,选择该猴群各一雄多雌单元(OMU)下地并进入投食区的取食时间、取食次数、取食顺序这3 个参数,通过计算各OMU 取食时的优势指数量化其取食优势从而对该猴群8 OMU 的等级地位进行了判断,结果表明这8 个OMU 的等级地位为:罗盘单元> 甲板单元> 八字头单元> 井字头单元> 刀疤单元> 朋克单元> 瑞星单元> 方片单元。此外,通过Spearman Correlation Test 将该方法的研究结果与利用攻击- 屈服行为优势指数法得到的研究结果进行了比较,二者具有极显著的正相关关系(R =0.976,P < 0.001)。可见, 利用取食参数的优势指数法判断各OMU 等级地位具有一定的可行性,且比攻击- 屈服行为的优势指数法在操作上更为简易,并以此试图为野外投食及笼养条件下非人灵长类等级地位的研究提供一个方法上的参考。     

秦岭川金丝猴一周岁内个体的行为发育

2003年3月至2004年5月在陕西周至国家自然保护区的玉皇庙地区,采用目标动物取样法(Focal ani-mal sampling)对2003年出生的5只金丝猴个体行为发育进行了观察,应用全事件记录法(All-occurrences record-ing)进行数据的收集。结果表明23日龄婴儿首次从母亲怀内爬出在树枝上活动,68日龄开始在树上攀爬跳跃,5月龄主动采食树叶和啃投食区食物,6月龄跟随社群迁移。依据婴幼儿主要行为首次出现时间及其变化,把1周岁内个体发育分为5个时期,即完全依赖期、探索外部世界期、融入社群期、适应生存期和逐步独立期。1周岁内婴幼儿活动和休息的地方是母亲怀里、其它个体怀里、树枝上和地面上。随着发育,婴幼儿在这些地方停留的时间也在变化。1周岁内婴幼儿在母亲怀中的时间与年龄存在明显的负相关,在其它个体怀里的时间与年龄也呈显著负相关。虽然独自在树上的时间与年龄相关性不显著,但在地面上停留的时间与年龄呈正相关。