Protecting the Habitat of Threatened Great Apes

Arcus Foundation

A unique species that was only identified in 2017, the Tapanuli orangutan is one of just eight great apes on the planet. But with a population of only 800 individuals, they have been critically endangered since the moment they were discovered.


The Tapanuli orangutan is found exclusively in the Batang Toru forest, on the island of Sumatra in Indonesia. The Tapanuli are under siege from a dizzying array of threats, with poaching, habitat loss, and climate change all pushing them to the brink. On top of these threats, a $1.6 billion hydroelectric power plant and dam was to be built in the middle of their habitat. The dam project threatened to permanently fracture their habitat, splitting the population into groups too small to survive and leading to the first great ape extinction in recorded history.


  •  North Sumatra Hydro Energy ultimately announced plans to delay the Batang Toru dam. This announcement followed our work with Mighty Earth and other allied organizations around the world to persuade the Bank of China to withdraw financing from the project.
  •  PLN, the Indonesian national utility, specifically cited environmental campaigning as a reason for the delay. 
  • We continue to work for landscape-scale protection for the whole of Batang Toru, which is home to many other critically endangered species including the Sumatran Tiger and pangolin.
All Work