Trending Science: New great ape, no sooner identified than on the endangered list

The remote groups of orangutan was discovered in the Batang Toru forest in Sumatra. Their numbers are so small, and their habitat so fragmented, that the scientists who identified the great apes fear they are in immediate danger of extinction.

The habitat of the newly discovered species is facing ever-increasing pressure from developers. The team behind a study recently published in the journal ‘Current Biology’ are reported in the Washington Post as saying, ‘If steps are not taken quickly to reduce current and future threats to conserve every last remaining bit of forest, we may see the discovery and extinction of a great ape species within our lifetime,’ they said.

First signs

In the mid 1990s, biological anthropologist Erik Meijaard, the founder of the conservation group Borneo Futures in Jakarta, discovered a paper written by a researcher exploring the area in the 1930s. He had written that there were reports of an isolated orangutan population, explains Nature news. The discovery of that paper prompted the team to go looking for the apes. Villagers showed researchers the remains of a female and a male orangutan killed by locals in 2013 and this provided key evidence: intact tissue and bone.

Genetic tests, field observations and a comparison of the male skeleton against 33 orangutan specimens in museums have revealed that the Batang Toru group is, in fact, a distinct species. Frizzier hair and a smaller head differentiates it from other species. Their diet and habitat, along with the male’s long-distance calls, also make them unique. Named Pongo tapanuliensis, the newly identified great ape is described in ‘Current Biology’ by a team that included most of the world’s orangutan experts. ‘It’s taken 20 years to come to the realisation of what this is,’ says Meijaard.

Fragile ecosystem makes the great apes vulnerable

The researchers found the apes in about three pockets within 425 square miles of forest, each separated by non-protected areas. They point out that for the apes to survive, the fragments of forest need to be interconnected by forest corridors. ‘It is imperative that all remaining forest be protected and that a local management body works to ensure the protection of the Batang Toru ecosystem,’ Matthew Nowak, one of the study’s authors told the Post.

The head of conservation of natural resources and ecosystems at Indonesia’s Forestry and Environment Ministry, who goes by one name, Wiratno, told a news conference in Jakarta that they were deeply committed to maintaining the survival of the species.

Although much of its habitat is protected by the Indonesian government, a proposed hydroelectric dam on the Batang Toru river would flood part of the area and divide the population in two, isolating the groups on either side of the river. That’s likely to further shrink the gene pool in the already inbred population, explains Meijaard. The dam would also bring more people to the area, potentially increasing hunting pressure.

‘It would be a bitter irony’, says Biruté Mary Galdikas, an orangutan specialist who founded Orangutan Foundation International, ‘if (the species) goes extinct as a biologically viable population just as it is described as a new species.’