Last year a motley crew of conservationists, adventurers and locals trekked into one of the last unexplored regions of Sumatra. They did so with a mission: check camera traps and see what they could find. The team – organized by the small NGO, Habitat ID – came back with biological gold: photos of Sumatran tigers, Malayan tapirs, and sun bears. They also got the first record of the Sunda clouded leopard in the area and found a specimen of a little-known legless reptile called Wegner’s glass lizard. But most tantalizingly of all is what they didn’t find, but still suspect is there: a hidden population of orangutans that would belong to the newly described species, Tapanuli orangutan (Pongo tapanuliensis).

“The trek into the interior was fraught with hordes of leaches, wasps, cliffs, river-crossings, and trackless jungle, and it pushed everyone on the team to their limits,” Greg McCann, the head of Habitat ID and a team member, said, clearly relishing the adventure to an undisclosed area they call Hadabaun Hills.

“The plateau, called Dolok Silang Liyang in the ethnic Batak language, means ‘the mountain where the wind rustles the leaves of the trees,’” he continues. “What we found there was a wet and misty world of mosses, lichens, and liverworts, of fallen trees and rotten logs and eerie silence. Sometimes we would fall up to our waists into bog-like earth of organic matter.”

A Sumatran tiger caught on camera trap in Hadabuan Hills. There are only a few hundred Sumatran tigers left on Earth. Photograph: Habitat ID

The team found that this remote area is especially important for Sumatra’s wild predators. In addition to tigers and clouded leopards, they recorded golden cats and marble cats.

“The single game trail that rings the 1,300-meter plateau seems to have been formed almost purely by the heavy footpads of tigers and also those of sun bears and golden cats,” says McCann.

McCann who headed the expedition along with tiger expert and local conservationist, Haray Sam Munthe, said they believe there might be 20-25 tigers in the region.

The team climbs treacherous terrain. Photograph: Arky

The Sumatran tiger is listed as critically endangered and is believed to have a global population of less than 600. But that estimate is eight years old – and recent years haven’t been good to Sumatran tiger as there are continual records of poaching and ongoing habitat destruction.

“Considering the perilous state of the Sumatran tiger today, as well as that of many other wild cats, the photographic evidence obtained by these camera traps set up in an ecosystem that has no official status should constitute a major discovery,” McCann said.

Few places have changed more radically in the last few decades than Sumatra. Half the island lowland forest has been lost, largely due to ever-expanding oil palm and pulp-and-paper plantations. Meanwhile, its species are declining to near-extinction levels. The Sumatran rhino only survives in a few tiny populations that, in total, numbers anywhere from 30 to 100 animals. In recent years, the Sumatran tiger, the Sumatran elephant and the Sumatran orangutan have all been uplisted to critically endangered.

The newly-uncovered Tapanuli orangutan is also desperately close to extinction. Experts estimate there are fewer than 800 left. Given this, a hidden population in Hadabaun would be very welcome news.



Julia Mörchen, an orangutan expert who accompanied the expedition, said the probability of orangutans in Hadabaun Hills was “high.” And she believes, if there, they probably belong to the newly described species though they may no longer be able to connect with the main population.

“It is likely that during the increasing agricultural development and human encroachment of the past decades in North Sumatra, the fragmentation of forests have led to the isolation of a small portion of orangutans,” she said.

Mörchen has spoken to two local individuals who have said they’ve seen orangutans, heard their calls and spotted their nests.



Two Malayan tapirs in one photo – one of them is possibly pregnant. The Malayan tapir is listed as endangered. Photograph: Habitat ID

Hadabaun Hills – home to at least seven other primates, seventy bird species (so far recorded) and ample fruit-bearing trees – is also prime habitat for orangutans, albeit at upper limits of their elevation preferences, according to Mörchen.

To find out if orangutans are really there, Mörchen says they “need funding” for an orangutan-specific expedition, which would include following local people to areas where the great apes have allegedly been encountered.

“The more time we have, the higher the chances to encounter them. I suggest a minimum of fourteen days, better to spend a month in the area,“ she said.

Yet, even as we study Sumatra’s great mammals, we know next to nothing about many of the island’s smaller animals, such as Wegner’s glass lizard. Currently, Wegner’s glass lizard is listed as data deficient by the IUCN Red List, which means scientists don’t have enough information to even determine if the species is at risk of extinction. But given that it’s only found in Sumatra and rarely encountered, it’s likely imperiled. This makes the discovery of this species on Hadabaun Hills all the more important.

A two hour boat journey up river. McCann said it felt like something “out of Apocalypse Now.” Photograph: Arky

The team also photographed the Sumatran laughingthrush on the forest floor – a rare behavior for this endangered species.



However remote, there are few – if any – areas left in Sumatra untrodden by poachers. During their expedition the team came on a poachers’ camp. They also photographed hunting dogs on their camera traps.

Unlike many conservation groups, Habitat ID is largely self-funded and operates on next-to-nothing. But McCann, a professor who lives in Taiwan, has long had a passion for unexplored places in Asia. He’s conducted similar camera trap surveys in Virachey National Park Cambodia, where he found elephants, Sunda pangolins and dholes – all in a protected area abandoned by bigger conservation groups.

“I rely greatly on the generosity of people who I have never met and who have never been to the places where I work but who have a curiosity about these places and this planet,“ says McCann, who depends partially on crowdfunding to keep the camera trapping and expeditions going.



McCann is returning to Hadabaun Hills at the end of the month to check the cameras and set new ones. He hopes for photos of a tiger with cubs or a tapir with babies – something that could rally the government to turn this place into a protected area. Habitat ID is also working the with the People Resources and Conservation Foundation to reach out to local people in the area, remove snares and stop further encroachment by the palm oil industry.

“There are few places like this remaining in Southeast Asia,” says McCann, “places where the rarest of rare species still lurk and prowl in secret retreats that only the craziest of explorers would try to reach.”

A Sumatran tiger on a camera trap in Hadabaun Hills. Photograph: Habitat ID

The expedition team enjoys a traditional Batak martial arts performance in a remote village. Photograph: Arky

A sun bear makes its way over a fallen tree. This species is listed as vulnerable. Photograph: Habitat ID

The partial remains of a muntjac head sitting in a poaching camp which the team disrupted. Photograph: Arky

A Sunda clouded leopard. This is the first record for Hadabuan Hills landscape. This species is listed as vulnerable. Photograph: Habitat ID

Conservationist, Andreas Neunert, searches the morning skies for hornbills. Photograph: Arky

A common barking deer, or muntjac, on camera trap. Photograph: Habitat ID

The team takes a much needed break while they scan the map to find the way. Photograph: Arky

An Asian golden cat caught on camera trap. This species is considered near threatened. Photograph: Habitat ID

A remote river in Sumatra. Photograph: Arky

Greg McCann, center foreground, enjoys the boat trip. Photograph: Arky

A Sumatran tiger that Greg McCann believes dwells within the territory of the local village. Photograph: Habitat ID

Greg McCann (left) and Julia Mörchen (right) gaze on more unsurveyed hills. Photograph: Arky

Traditional music performed in a remote village to welcome the travelers. Photograph: Arky

Misty morning mountains beyond the Hadabuan Hills. Photograph: Arky