Rare orangutan species faces extinction after devastating Indonesia floods

Local rangers say they are struggling to find the primates in an area where sightings were common prior to the disaster

Indonesia’s deadliest floods in decades have pushed the world’s rarest great ape closer to extinction, as scientists warn that vast swathes of forest critical to the survival of the Tapanuli orangutan have been destroyed by landslides and extreme rainfall.

Conservationists say the cyclone-driven floods and landslides that tore through parts of North Sumatra late last month did not just kill hundreds of people but also devastated the fragile habitat of the critically endangered species, which exists only in a small mountainous region of the island.

The Tapanuli orangutan was formally recognised as a distinct species only in 2017 and is already teetering on the brink of extinction. Fewer than 800 are believed to remain in the wild, all confined to the Batang Toru ecosystem in Sumatra.

Local rangers say the animals have all but vanished from areas where they were regularly seen before the disaster.

“After the landslides hit, the orangutans are nowhere to be seen,” said Amran Siagian, a ranger with the Orangutan Information Centre (OIC) who has worked in the forests around Sipirok in South Tapanuli for five years. “I could no longer hear their voices,” he told Reuters.

Deckey Chandra, another humanitarian worker, told the BBC: "They used to come to this place to eat fruits. But now it seems to have become their graveyard."

Indonesia’s floods and landslides, triggered by extreme rainfall linked to Cyclone Senyar, have killed more than 900 people nationwide, with hundreds still missing. Entire hillsides collapsed, washing away forests, farms and villages, and cutting off remote communities.

Satellite imagery and on-the-ground assessments suggest that large sections of the Batang Toru forest were stripped bare as torrents of mud, trees and water tore through steep terrain.

A drone view shows Bulu Mario village of Sipirok in South Tapanuli (REUTERS)

Conservationists have confirmed at least one orangutan death, and warn that more may have been killed but not recovered in areas buried under debris.

Panut Hadisiswoyo, founder of the Orangutan Information Centre, said the loss of even a single animal was a setback for the species.

The flooding has compounded pressures already facing the apes. “The major threat is the loss of forest due to plantations and extractive industry,” he told Reuters.

Environmental groups have long voiced alarm that deforestation linked to logging, mining and plantation expansion has weakened hillsides and increased the risk of catastrophic landslides in the region.

In Sipirok, trees appeared to have been cut down in areas hit hardest by the floods. Mr Siagian said logging had been taking place there for at least a year before the disaster, fragmenting the forest canopy that orangutans rely on to move, feed and breed.

“The orangutans live by moving between forest canopy, from branch to branch,” he said. “If the forest is sparse, it must be difficult for them.”

Scientists warned that the floods amounted to an extinction-level disturbance for the species.

“We think that between six and 11 per cent of orangutans were likely killed,” Erik Meijaard, a longtime orangutan conservationist, told the AFP news agency.

“Any kind of adult mortality that exceeds one percent, you’re driving the species to extinction, irrespective of how big the population is at the start,” he said.

Scientists confirmed this week that hotter ocean temperatures due to the heating cliimate intensified rainfall across Southeast Asia. Warmer seas and heavier downpours have increased the likelihood of destructive flooding and landslides, particularly in deforested or heavily developed areas.

Conservationists are urging authorities to halt further development in the orangutans’ remaining habitat, expand protected areas and carry out urgent surveys to assess population losses.

“If there is no government help, the orangutans could go extinct here,” Mr Siagian warned. “Especially with this massive deforestation.”