Borneo has 19.8 million inhabitants (in mid-2010), a population density of 26 inhabitants per square km. Most of the population lives in coastal cities, although the hinterland has small towns and villages along the rivers. The population consists mainly of Dayak ethnic groups, Malay, Banjar, Orang Ulu, Chinese and Kadazan-Dusun. The Chinese, who make up 29% of the population of Sarawak and 17% of total population in West Kalimantan, Indonesia are descendants of immigrants primarily from southeastern China.
Borneo’s primate community is exceptionally rich. The Earth Expeditions course site along the Kinabatangan River in Sabah (East Malaysia) is home to ten primate species, including proboscis monkeys, which occur only in Borneo, two species of leaf monkey, two species of macaque, gibbons, as well as the large-eyed, nocturnal tarsier and slow loris.
Of greatest conservation concern is the orangutan, which occurs naturally on only two islands in the world, Borneo and Sumatra, and is under increasingly severe pressure, primarily from habitat loss. Researchers have projected that the orangutan, the only great ape in Asia, may completely vanish from the wild within two decades.