Indonesia floods 'extinction level' for rare orangutans

SUMARTA

Indonesia's deadly flooding was an "extinction-level disturbance" for the world's rarest great ape, the Tapanuli orangutan, causing catastrophic damage to its habitat and survival prospects, scientists warned on Dec. 11.

Only scientifically classified as a species in 2017, Tapanuli orangutans are incredibly rare, with fewer than 800 left in the wild, confined to a small range in part of Indonesia's Sumatra.

One dead suspected tapanuli orangutan has already been found in the region, conservationists told AFP.

"The loss of even a single orangutan is a devastating blow to the survival of the species," said Panut Hadisiswoyo, founder and chairman of the Orangutan Information Center in Indonesia.

And analysis of satellite imagery combined with knowledge of the orangutans’ range suggests that flooding last month which killed nearly 1,000 people may also have devastated wildlife in the Batang Toru region.

The scientists focused on the so-called West Block, the most densely populated of three known habitats, and home to an estimated 581 Tapanuli orangutans before the disaster.

There, "we think that between 6 and 11 percent of orangutans were likely killed," said Erik Meijaard, a longtime orangutan conservationist.

"Any kind of adult mortality that exceeds 1 percent, you're driving the species to extinction, irrespective of how big the population is at the start," he told AFP.

Satellite imagery shows massive gashes in the mountainous landscape, some of which extend for more than a kilometer and are nearly 100 meters wide, Meijaard said.

The tide of mud, trees and water toppling down hillsides would have carried away everything in its path, including other wildlife like elephants.