BORNEO’S population of orangutan has experienced a sharp decline in recent years as hunting and logging have led to the loss of nearly 150,000 of the primates from the island’s forests, conservationists warn.
A new report, published in the journal Current Biology, estimates that the number of orangutans left on Borneo now stands at between 70,000 and 100,000, meaning the population more than halved over the study period which ran from 1999 to 2015.
While the steepest declines were recorded in areas where the forests were cleared to make way for palm oil or acacia plantations, this actually only accounted for a small proportion of the overall loss.
100,000 Borneo orangutans have been killed over 16 years. Their forest homes have been lost & degraded, & hunting threatens their existence. We must put pressure on companies to commit to a sustainable supply of palm oil that isn’t devastating this critically endangered species pic.twitter.com/KoDIX36Rko
— WWF UK (@wwf_uk) February 16, 2018
Far higher numbers were lost in areas where the forest remained undisturbed by logging and deforestation. Researchers suggest this points towards hunting playing a major role in the population’s decline in these forested regions.
This “pervasive decline” of orangutans in more intact habitat is consistent with a number of other studies identifying hunting as the main driver of biodiversity loss in the tropics, including Southeast Asia, the report said.
Through extensive interview surveys in Kalimantan, where the highest abundance of orangutans are found, researchers found on average 2,256 orangutans were hunted or killed annually due to conflict with humans.
The report also cited the national and international wildlife trade, in which orangutans are traded, as a driver in the decline.
“Traded orangutans are usually young orphans,” the report said. “For each orphan, adult individuals have been killed. Due to the low reproductive rate of the species, even very low offtake rates of reproductive females will drive populations to extinction.”
— Liverpool John Moores University (@LJMU) February 16, 2018
Effective partnerships with industrial players – namely logging companies, and oil palm and paper pulp producers – are essential to promote “best practice guidelines for management,” the report said. It is hoped such partnerships could improve biodiversity in general throughout the region and improve the prospects for the “critically endangered” orangutan.
Without fresh efforts to protect the animals, the numbers could fall at least another 45,000 in the next 35 years, the conservationists predict. The real decline could be worse as the prediction is based only on habitat loss, and does not include killings.
According to the researchers, biodiversity conservation needs to “permeate into all political and societal sectors” if we are to prevent further damage to the Bornean apes. Urging for immediate action, the researchers call for conservation to become a “guiding principle in the public discourse and in political decision-making processes.”
“To prevent further decline and continued local extinctions of orangutans, humanity must act now.”