Researchers at the University of Zurich have discovered a new species of orangutan. The news species, Pongo tapanuliensis (Tapanuli orangutan), live in remote areas of rainforest in Batang Toru,  on the Indonesian island of Sumatra. It was previously thought there were only two orangutan species. There are only 800 of these great apes remaining, making them the ape species with the highest risk of extinction.