REPORT ON THE DISTRIBUTION, POPULATION, AND ECOLOGY OF THE YUNNAN SNUB-NOSED MONKEY (RHINOPITHECUS-BIETI)

The Yunnan snub-nosed monkey (Rhinopithecus bieti), an endangered spec ies in China, has received more protection in theory than in practice. Therefore it is on the very verge of extinction. The population of th e species was estimated less than 2,000 individuals spread in 19 disti nct groups. It was confirmed that the monkey was confined to the Yunli ng Mountain System, the area between the Yangtze River (Changjiang, ak a Jinshajiang) to the east and the Mekong River (Lancangjiang) to the west. We further concluded that a lowland belt to the east, about 100 km long and 20 - 30 km wide was not suitable habitat for the monkeys, and appeared to serve as the natural ecogeologic barrier for the speci es. Our results indicated that the southern limit of the distribution was at Longma (26-degrees 14'N), and that the northern limit of the di stribution was at Xiaochangdu (29-degrees 20'N). The distribution area of the species was substantially smaller than previously estimated. T here were substantial ecological differences between the southern and northern parts of the species range. The monkey was found only in fir- larch forest.