The mammal species of Borneo include 288 species of terrestrial and 91 species of marine mammals recorded within the territorial boundaries of Brunei, Indonesia and Malaysia. The terrestrial mammals are dominated by the chiroptera (102 species of bats) and rodents (61 species of rats and mice).
The high diversity and endemicity of mammals is related to the many niches found in the tropical rain forest of Borneo and past Pleistocene events within the Sundaland region. During interglacial and post-glacial periods, there was migration of animal from the Asian mainland into Borneo and into Sulawesi via the Philippines. Due to lack of favourable habitats and small founder population, some species of animals have become extinct and others have radiated into endemic species. Of the 57 mammal species that were identified from archaeological remains in the Niah Caves, Sarawak, 13 were bats. Four of these were megachiropterans, Pteropus vampyrus , Rousettus amplexicaudatus , Rousettus sp and Eonycteris spelaea , all of which remain extant species in Borneo and Peninsular Malaysia. The provisional list of mammals of Borneo (sensu Lord Medway, Payne et al., Corbet and Hill, Koopman, and Wilson and Reeder) are listed below. There are various conflicts in the taxonomic lists by previous authors, which need further field research for validation.
The following list gives the scientific name followed by the common names, description, ecology, conservation and distribution information.