• deforestation;
  • great apes;
  • hunting;
  • Indonesia;
  • Malaysia;
  • nongovernmental organizations;
  • orangutan;
  • palm oil;
  • plantations;
  • Pongo abelii;
  • Pongo pygmaeus

Orangutan survival is threatened by habitat loss and illegal killing. Most wild populations will disappear over the next few decades unless threats are abated. Saving orangutans is ultimately in the hands of the governments and people of Indonesia and Malaysia, which need to ensure that habitats of viable orangutan populations are protected from deforestation and well managed to ensure no hunting takes place. Companies working in orangutan habitat also have to play a much bigger role in habitat management. Although the major problems and the direct actions required to solve them—reducing forest loss and hunting—have been known for decades, orangutan populations continue to decline. Orangutan populations in Sumatra and Borneo have declined by between 2,280 and 5,250 orangutans annually over the past 25 years. As the total current population for the two species is some 60,000 animals in an area of about 90,000 km2, there is not much time left to make conservation efforts truly effective. Our review discusses what has and has not worked in conservation to guide future conservation efforts.