Preliminary observations of the Mentawai snub-nosed langur (Simias concolor) on islets in the south Pagai region, Mentawai, West Sumatra : habitat, behavior, and conservation

The colobine monkey Simias concolor, endemic to the Mentawai Islands, West Sumatra, Indonesia, was studied on two is l ets adjacent to South Pagai. Habitat on these islands was observed and described, and observations were made there from September to November 1987. Group sizes ranged from 2 to \u3e10. Population density may vary with habitat structure. Social groups appear to include one or more females. Contrary to some reports, male and female animals are sexually dimorphic. Inability to identify specific animals or groups prevented mapping of home range areas. Observations are correlated with what has been previously reported about this animal. Future research could be focused on further studies of habitat use and ranging behavior, determination of Simias population densities in possible reserve areas, interspecific interactions, and dietary composition. Without such studies, it is unlikely that adequate management plans can be devised. Prospects for the conservation of this species are reviewed. Suggestions which have been advanced to promote its conservation are also evaluated. The fate of this animal is strongly linked to local, provincial, and national cultural and developmental factors. These include forestry operations, agriculture, hunting, population growth, and transmigration plans