Asian colobines are a diverse group of leaf-eating monkeys, with at least 55 species recognized within seven genera (Nasalis, Presbytis, Pygathrix, Rhinopithecus, Semnopithecus, Simias, Trachypithecus) . They are characterized by having large, multi-chambered stomachs that contain vast array of microflora needed to process and ferment plant material. Thus they exhibit some generalized pattern of leaf preference in their diet, but also consume significant amount of other plant parts.
Asian colobines are found in a multitude of habitats from tropical and subtropical forests (e.g. Javan leaf monkey, Presbytis comata), swamp forests (e.g. Raffles' banded langur, P. femoralis femoralis; proboscis monkey, Nasalis larvatus), along coastlines (e.g. silvered leaf monkey, Trachypithecus cristatus), and in mountains as high as 4,700m in elevation (e.g. black snub-nosed monkey, Rhinopithecus bieti).
The primates of Vietnam are one of the top global priorities for primate conservation. Nearly 90% of Vietnamese primate species are threatened. All 12 species of colobines are either critically endangered or endangered. Most populations inhabit forest fragments which face continued fragmentation due to human activities. It is becoming increasingly important to examine the genetic variability of small and isolated populations in order to assess the viability and conservation status of threatened species.
Main research focus:
Conservation status follows IUCN 2013.2