The Tapanuli orangutan Pongo tapanuliensis was discovered around 2017 in the Batang Toru Ecosystem, in the province of North Sumatra, the first new Great Ape to be found in a century. Only 800 individuals are believed to exist. This immediately makes the Tapanuli orangutan the most critically endangered Great Ape on earth. While protections have been achieved for nearly 85% of this red apes habitat, two potentially devastating industrial projects, a hydro dam and a gold mine expansion, are proposed in a sensitive area of connectivity inside the unprotected part of the forest.
In November 2017, scientists found that the orangutans in Tapanuli are a distinct species and not a subspecies of the Sumatran orangutan. They gave them the name Pongo tapanuliensis. Recent genetic analysis reveals that the new species is actually more closely related to the Borneo orangutan Pongo pygmaeus pygmaeus than to the Sumatran orangutan Pongo pygmaeus abelii. It is considered to be the ‘ancestral line’ from which the other two subspecies evolved when line it split 670,000 years ago.
Tapirs, Sun Bears, Sumatran Serow, Golden Cats and the critically endangered Sumatran tigers are also found in the forests of Batang Toru.
800 individuals – the last of their kind – live in the forests south of Lake Toba. Part of Batang Toru forest is protected, but other ecologically valuable areas with a particularly high orangutan population are not. The state-owned Chinese hydropower company Sinohydro wants to build a dam for a 510MW power plant in Batang Toru Forest, The dam would destroy the habitat of the Tapanuli orangutan and also isolate the individual orangutan populations from one another.