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Wildlife and Biodiversity

The Leuser Ecosystem is home to the largest extent of intact forest landscapes remaining in Sumatra and it is among the most biologically abundant landscapes ever described.


Scientists and conservationists consider the Leuser Ecosystem to be among the most important forests left in Southeast Asia, particularly because it is the last place of sufficient size and quality to support viable populations of rare species like Sumatran tigers, orangutans, rhinos, elephants, clouded leopards and sun bears.

At least 105 mammal species, 382 bird species, and 95 reptile and amphibian species, including clouded leopards, hornbills and the largest flowers in the world, can be found in the teeming forests of the Leuser Ecosystem. Formerly known as the “Emerald Island,” Sumatra’s once lush forest landscapes are now largely gone, destroyed by decades of industrial encroachment.

The Sumatran orangutan is at extreme risk of becoming the first great ape to go extinct in the wild. The last major stands of habitat for the Sumatran orangutan are found in the Leuser Ecosystem, which supports about 75 percent of the world’s remaining population. In order to save the Sumatran orangutan from extinction, we must protect the integrity of the Leuser Ecosystem. Other critical species face a similar fate. The Sumatran tiger is thought to number just a few hundred individuals left, the Sumatran rhino even fewer still, with the Sumatran elephant similarly imperiled.

The Leuser Ecosystem is truly the last stand for survival for many treasured and iconic wildlife species.

See more: The Leuser Ecosystem, In Pictures