In The RED: New Threat To The World’s Rarest Ape

The critically endangered Tapanuli orangutan was only just discovered in 2017, and now the world’s newest – and rarest – ape is under threat from a hydroelectric dam.

New Discovery

The Tapanuli orangutan was officially described for the first time on 2nd November 2017. With a population of only 800 individuals remaining, it is classified as a critically endangered species. Up until then, scientists had recognised just two species of orangutans: Bornean and Sumatran. But the Tapanuli species is distinct from the other two in several keys areas, including having ‘frizzier’ hair. Males have smaller skulls, prominent moustaches and long booming calls that differ from the males of other orangutan species, whilst the females (as pictured here) have distinct beards.

Batang Toru

The new species, which has been classified as Pongo tapanuliensis, lives in the Batang Toru forests of northern Sumatra. Little more than a year after it was officially named, the orangutan’s habitat (the only place in the world where it is found) is now under threat from a hydroelectric plant and dam. The Chinese-financed project and its associated infrastructure, including roads and an 8-mile long tunnel, will permanently fragment the animal’s habitat.

Habitat Fragmentation

Forest clearance has already begun for the hydroelectric power plant. The dam itself is to be built in the orangutans’ most critical habitat, an area with the highest density of individuals. Only one population – numbering around 500 orangutans – is considered large enough to remain viable. Already, construction activity has driven some of the orangutans out of the project area and into nearby plantations. Scientists are convinced that any further fragmentation of its habitat will push the species to extinction.

As a tree-dwelling species that rarely touches the ground, the Tapanuli orangutan is highly susceptible to habitat fragmentation. A road through the forest would represent a barrier to movement, effectively trapping the apes in small pockets of forest and cutting them off from each other.


The Batang Toru forest is one of the most biodiverse regions in Indonesia, home to the critically endangered Sumatran tiger, Sunda pangolin and helmeted hornbill. Rare sun bears, tapir, and a host of other species, including more than 300 birds, can also be found in this rich landscape of lowland tropical jungle and mossy mountainous forest. Forest clearance doesn’t just threaten the orangutans; its impacts will have wide-reaching consequences for much of Batang Toru’s flora and fauna.

Behind the Scenes

Tim Laman, who was awarded the title of Wildlife Photographer of the Year in 2016 for his image of a Bornean orangutan climbing into the canopy, is one of a handful of photographers who have made the trek into the remote Batang Toru region to photograph the Tapanuli orangutan in the wild. ‘‘Photographing critically endangered species, like the Tapanuli orangutan, is important for a number of reasons,’’ says Tim.

‘‘We know so little about this species that every image we capture can be an important record for research. I’ve been photographing Bornean orangutans for over twenty years, but in my short visit to document Tapanuli, I photographed them doing things I had never seen before, like drinking from a pitcher plant, and feeding on caterpillars. Like other orangutan populations, the Tapanuli is certain to have a rich trove of cultural knowledge that is passed on from parent to offspring, and between individuals, about how to survive in that forest, and it would be a shame to lose that if this species disappears. One thing I really don’t want my pictures to be is a record of an extinct species. Instead, my hope is that these images can inspire people to care for this unique orangutan population and its habitat.’’

Batang Toru Dam

The Batang Toru dam is scheduled to begin operations in 2022, periodically storing water and releasing it in massive surges, impacting the river and increasing the risk of flooding in downstream communities. Experts question the need for a new power plant in Sumatra. The country currently produces a surplus of electricity, and it would be possible to expand the capacity of existing plants (including a geothermal project near Batang Toru) without impacting the orangutans. Moreover, the hydroelectric project is being built in a region prone to dangerous earthquakes.

Global petitions asking for the project to be cancelled have gathered momentum, and scientists have appealed directly to the Indonesian President. In March 2019, a lawsuit brought by a green group against the government claimed the permit for the dam was issued illegally, with one scientist claiming the application failed to publish his full impact assessment, and forged his signature. Within days of the lawsuit being defeated in court, a major Chinese state-owned bank helping to fund the hydro-power dam promised to evaluate the project. Some activists are hopeful this will achieve what the lawsuit couldn’t, but others are sceptical, dismissing the statement as hollow green-wash.

  1. A juvenile female orangutan, named Beti by researchers, plays in a tree with her mother Beta. Orangutans are slow to reproduce, giving birth to one (or sometimes two) offspring every eight to nine years. This makes them highly sensitive to disturbance; a diminished population would struggle to recover fast enough to avoid extinction.
  2. Togus, an adult flanged male feeds on flowers. The Tapanuli orangutan’s diet is similar to that of other orangutan species—they eat a lot of fruit, leaves, saplings, buds, and small insects; however, they are the only species known to eat pine cones and caterpillars.
  3. Tapanuli orangutans live in a tiny tract of forest less than one-fifth the size of Indonesia’s capital, Jakarta. Because most of the lowlands surrounding their habitat have already been converted for agriculture, the remaining forest is crucial to their survival.

A Global Treasure

‘‘Having discovered an additional cousin in our family tree, there is so much more we can learn about them,’’ says Tim Laman. ‘‘But they need to have a secure forest home for the indefinite future. My hope is that the Indonesian people and leaders will make the commitment to be the guardians of this global treasure.’’

The fate of the Tapanuli orangutan, one of our closest relatives on the planet, now lies with the Indonesian people. Will the forces of big business win out, or will the call of conservationists, global campaigners and local Indonesian villagers be heard, securing a better future for the world’s rarest ape?

Click here to view the full gallery of images, or check out the pdf here.