The Research On Allogrooming Behavior Of Sichuan Snub-nosed Monkey (Rhinopithecus Roxellana)

Allogrooming is probably the most common social behavior within Rhinopithecus roxellana. Sichuan snub-nosed monkeys spend most of their daily time grooming with each other which is significant for progressing the relationship among individuals. However, studies about allogrooming in Sichuan snub-nosed monkeys confine to the hygienic functional hypothesis. In order to test whether allogrooming play other functions such as exchanging function, we investigated the allogrooming behavior in a provisioned band of Sichuan snub-nosed monkey in Shennongjia Nature Reserve Hubei, China. This study was conducted in the area of Dalongtan (110°18’E,31°29’N) between July2010and October2011. Focal animal sampling and behavior sampling were used to observe the individuals, besides, data were recorded with continuous recording. Results show that:Adult females and the resident male were most often involved in grooming interactions. In mating season, grooming frequencies given to the single resident male by females was significantly higher than in reproductive season (t=3.523, p=0.006), as well as the grooming frequencies given from the single resident male to females (t=2.775, p=0.020). Furthermore, compared with others, females without infants tended to groom the single resident male more in mating season (t=-2.497, p=0.034). Grooming between females appeared more in the reproductive season than in the mating season (t=-4.699, p=0.001), moreover, females with newborns received more grooming from others who wanted to get the infants.Compared with the usual, both females and the single resident male groomed the sexual partners more after copulation (female to male: t=-4.711, p=0.001; male to female: t=-9.655, p<0.001), moreover, after copulation, the mean duration of each grooming bout that females gave to the single resident male was also significantly longer than usual (t=-8.206, p<0.001) which makes grooming seeming to be a payment for mating behaviors.The ratio between grooming frequencies of given bouts and received bouts was significantly negatively related to the females’dominance hierarchy (DD unit:rs=-1.000, N=5,p <0.001; XX unit:rs=-0.943, N=6, p=0.005). In addition, the ratio between mean grooming duration of given bouts and received bouts was also negatively ralated to the females’dominance hierarchy (DD unit:rs=-0.900, N=5, p=0.037; XX unit:rs=-0.886, N=6,p=0.019). Overall, we concluded that there are some strategies on allogrooming behavior in the Sichuan snub-nosed monkey. Although individuals with different requires have their respective tactics, they always distribute more grooming to those individuals with rare and valuable resources. It indicates that allogrooming can be exchanged as a commodity and supports the biological market theory.