This research addressed two important issues concerning conservation of orang-utans in Indonesia, the prevalence of diseases in orang-utans at reintroduction centres and the extent of intra-subspecific genetic variation between isolated populations of Bornean orang-utans. The research was conducted at the Wanariset Orang-utan Reintroduction Centre in East Kalimantan from 1994 to 1997, and at the Biomedical Primate Research Centre in the Netherlands in 1998. Studies were designed to identify and determine the prevalence of diseases, specifically gastro-intestinal parasites, tuberculosis and...