In addition to orangutans, Sumatra is home to many other keystone species. Most Sumatran orangutans live in the Leuser Ecosystem, which contains some of the last intact tropical lowland rainforest on the planet. This ecosystem supports the largest remaining populations of Sumatran tigers, Sumatran elephants, and Sumatran rhinos, as well as 95% of the remaining Sumatran orangutans. It is the only place left in the world where all four species coexist in the wild. Preserving the orangutan's habitat also helps these other species.