Borneo (administratively divided between Indonesia, Malaysia and Brunei) is the third largest island in the world. Borneo is only a western reference and the term is rarely used locally; the name Borneo itself was only given by the Dutch during their colonial period. In Indonesia, the island is always referred to as Kalimantan while in Malaysia the northern section is referred to as East Malaysia, as opposed to western reference of Malaysian Borneo.

Ecology

Borneo is very rich in biodiversity compared to many other areas.  There are about 15,000 species of flowering plants with 3,000 species of trees (267 species are dipterocarps), 221 species of terrestrial mammals and 420 species of resident birds in Borneo (MacKinnon et al. 1998). It is also the centre of evolution and radiation of many endemic species of plants and animals. The remaining Borneo rainforest is the only natural habitat for the endangered Bornean orangutan. It is also an important refuge for many endemic forest species, and the Asian Elephant, the Sumatran Rhinoceros and the Clouded Leopard.
The island historically had extensive rainforest cover, but the area is shrinking rapidly due to heavy logging for the needs of the Malaysian plywood industry.

Ethnic and Biological Diversity

There are over 30 ethnic groups living in Borneo, making the population of this island one of the most variegated of human social groups. Some ethnicities encompass only between 30-100 individuals and are threatened with extinction in terms of culture, language, traditional ecological knowledge, traditional skills, ethnomusic  and local knowledge yet to be documented by anthropologists. Ancestral knowledge of ethnobotany  and ethnozoology  is said to be useful in new drug discoveries (e.g bintangor plant for AIDS) or as future alternative food sources, e.g. sago starch for lactic acid production and sago maggots as a protein source.
Researchers scouring swamps in the heart of Borneo island have discovered a venomous species of snake that can change its skin color. Scientists named their find the Kapuas mud snake, and speculated it might only occur in the Kapuas River drainage system.
World Wildlife Fund has stated that 361 animal and plant species have been discovered in Borneo since 1996, underscoring its unparalleled biodiversity. Furthering the unparalleled biodiversity of the island of Borneo, in the 18 month period from July 2005 until December 2006, another 52 new species were found.