The World's 25 Most Endangered Primates is a list of highly endangered primate species selected and published by the International Union for Conservation of Nature Species Survival Commission Primate Specialist Group, the International Primatological Society, and Conservation International. The countries with the most species on the list are Madagascar and Vietnam with five species each, and Indonesia with four species. The list has been published five times, with seven species appearing on all five lists: the silky sifaka (pictured), Delacour's langur, golden-headed langur, grey-shanked douc, Tonkin snub-nosed monkey, Cross River gorilla, and Sumatran orangutan. The two greatest threats that primates face are habitat loss and hunting. More specifically, threats listed in the report include deforestation, forest fragmentation, small population sizes, live capture for the exotic pet trade, and hunting for bushmeat and traditional medicine. (Full list...)