Survival Strategy Of All-male Unit Individuals In A Troop Of Provisioned Yunnan Golden Monkeys (Rhinopithecus Bieti)

All-male uint (AMU) is the basic social structure of genus Rhinopithecus, it is living with other one-male units (OMU) and then form an unique multi-level social structure unlike other asian colobines. Previous study on the genus are mainly on the OMU's social function and survival fitness, little attention is paid on AMU, so from July 2009 to Sept 2010, we have used focal animal sampling and behavior sampling to observe and continuous sampling to record, taken the AMU in a band of provisioned Yunnan golden monkeys (Rhinopithecus bieti) located in Xiangguqing, Baimaxueshan National Nature Reserve as our focal subject, in an attempt to find out what strategy does the AMU individuals take to survival in their nature and social environment. We found that the AMU individuals take the following strategies to fit the environment: In feeding related behavior, AMU is always walking in the front of the band when the band is moving, to have high quantity food prior to OMU individuals; when in feeding site, AMU individuals usually spread wide in the redge of the band to increase feeding efficiency, AMU individuals spread wider when feeding compared with when they are resting, and they spread more wide than OMU individuals when feeding; and in order to get enough energy, they spend more time in feeding than OMU individuals, 28 cases of the detailed time that AMU and the last OMU finished their feeding were recorded, AMU spend 34.4±5 mins more than OMU in feeding.In avoiding be predated, AMU individuals take the flee strategy the same as OMU individuals when facing the potential risk; and living with other OMUs is also an important way to reduce predation pressure.In reproductive related beahviors, different from resident males, adult and subaudlt individuals in AMU are more intersted in mate with females, in mating cases between AMU individuals and females,20 cases (66.6%) of them are initiated by AMU individuals, they are the active sponsor and participator of mate behavior with females and an active respondent when facing the females'solicit mate; and adult individuals will gain their reproductive access to females in the frm of takeover,4 cases of male takeover were recorded acrossing the field study period,4 males become the new resident male in the form of male takeover; and some adult males will leave their original band to wander around to other band to see if there is a chance for them to form an OMU their own,11 cases of the "wander adult male" visited the study band's home range, and 4 wander males gain their reproductive access to females in the form of male takeover in the study band.In dealing with Social relationship, different from resident males'fighting way, AMU individuals are always try to avoid phycial contact when there is a conflicit, AMU members are always solve the conflicit in the form of approach-retreat and threat-surrender way to save energy and avoid getting hurted; and adolescents living with other adults and subadults form the AMU and then further form the big band is also a way to fit the environment, though form a big band have its disadvantage. AMU individuals can balance those disadventages in other way, such as the strategies mentioned above.