The primary predators currently of Sumatran orangutans are humans (Homo sapiens). Hunting of orangutans has decimated their populations. Natural predators of Sumatran orangutans are clouded leopards (Neofelis nebulosa) and Sumatran tigers (Panthera tigris sumatrae). These predator species are also under threat of extinction due to hunting by humans.
- MacKinnon, J. 1974. In Search Of The Red Ape. Ballantine Books; A Division of Random House, Inc. New York, NY: Holt, Rinehart and Winston.