This project investigates patterns of social interactions and kinship networks of a highly endangered Asian colobine (Rhinopithecus roxellana) in China. Ultimate goals of this study are to explore the evolution of primate sociality, as well as the role of kin and non-kin affiliation and cooperation in the formation of social networks in nonhuman and human primates by studying the uncommon social structures exhibited by R. roxellana. R. roxellana is reported to exhibit a multilevel social system composed of over 100 members in which individuals form one-male-units (OMUs, which include one adult male, several adult females and their offspring), all male units, and bands (several OMUs that travel, feed and rest together). Multi-level societies are rare in primates, and have only been reported in two other species (geladas (Theropithecus gelada), and hamadryas baboons (Papio hamadryas)). Little is known, however, concerning the set of social and ecological factors that promote and maintain stability and tolerance among members of a multi-level social system, and the degree to which individuals residing in the same OMU and band are related. In this project, a 13-month field study of adult individuals of a habituated band of R. roxellana will be conducted. Fecal samples will be collected from adult band members and extract DNA. Two genetic markers, mitochondrial DNA (mtDNA) and microsatellite DNA, to estimate relatedness among band members will be employed. Combed data on affiliative, agonistic, and cooperative behavior with genotype data, will serve to test theories of kin selection, reciprocity, biological markets, and byproduct mutualism in explaining social interactions among individuals of R. roxellana societies.
The results of this study will help to identify the social and ecological costs and benefits to individuals of forming large, coordinated, and highly flexible social units. In addition, data on the genetic diversity in approximately 50 Sichuan snub-nosed monkeys will be obtained. This species is highly endangered. Detailed data on social behavior and genetic structure of this species will yield information on their residence patterns, immigration rates, and dispersal distance. Such information is critical for the design and management of natural reserves for R. roxellana.
