The Bornean orangutan (Pongo pygmaeus) is now critically endangered due to habitat destruction, habitat degradation, habitat fragmentation, and illegal hunting, as declared by the International Union for Conservation of Nature (IUCN). It has been estimated by the World Wildlife Fund (WWF) that only 45,000 – 69,000 Bornean orangutans remain.

The Bornean orangutans now join their cousins, the Sumatran orangutans (Pongo abelii), which have been listed as critically endangered since 2008, with only about 14,000 remaining today. This change signifies that orangutans face an “extremely high risk of extinction in the wild” (IUCN), as both living species are now considered critically endangered.

Bornean orangutans live only on the island of Borneo, and have declined in population by 60% since 1950. It is estimated that their population will fall another 22% by 2025, equating a total 82% population loss between 1950 and 2025.

This meets the criteria for the IUCN’s definition of critical endangerment: “an observed, estimated, inferred, projected, or suspected population size reduction of above 80% over any ten-year or three-generation period.”

Andrew Marshall, who was part of the IUCN assessment, made a statement to Mongabay saying that despite past conservation efforts, orangutan conservation is still failing as it has not yet reached stable or increasing population, and Borneo’s rainforests continue to be poorly monitored.

Only 59.6% of Borneo’s rainforests were suitable for its orangutans in 2010. With continued illegal hunting and habitat degradation among other threats to the population, this number has only dwindled further. In addition to this, many orangutan populations in these areas are settled in smaller patches of the forest which are or soon will be unable to sustain the groups living there. While these populations have the opportunity to adapt to survive (and orangutans are fairly keen on adaptation), poor health and smaller numbers will likely interfere with reproduction and population upkeep.

This study by the IUCN is the first good look in decades at the Bornean orangutan population. “The problem with assessing species like orangutans is there is such a long time-lag effect. Many populations in these forest fragments may be heading toward extinction already, and the grim reality is there is little we can do to alter this trajectory,” said Marshall. “We could remove every threat right now, and many populations would continue to decline for several generations.”

These mammals are incredibly long-lived, have long generations, are long to reach sexual maturity (around 11 years old for females), and have the longest birth interval of any land mammal. This together with the ever-increasing threats to the population have contributed to the difficulties in assessment by the IUCN.

John Platt, who has written about orangutan conservation for over a decade, points to the Indonesian and Malaysian government as a point deserving crucial attention: until these government systems get a handle on illegal deforestation, uncontrolled burning, and the poor practices of legal industries in the rainforest, the Bornean orangutans will only continue to see a population decline.However, this label does not guarantee extinction. Researchers and animal advocates are keeping their optimism. Indonesian president, Joko Widodo, has said he would work to limit the palm oil industry’s growth in an effort to protect the animals who live in these rainforests. If these policies are properly enforced, the orangutans still have a good chance at survival.

Marshall has proposed that we place a higher conservation concern and value on degraded lands as well as look for approaches to conservation which engage with industries that have long been considered adversaries to the environmentalist cause. In order to move forward, we must look to engage directly with these issues and industries to find how best to protect all species of these rainforests.

“Although I think things will likely get worse before they get better,” Marshall said, “it’s not too late for orangutans.”

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To learn more about the Bornean orangutans, visit the IUCN Redlist. To find out how you can help, visit the World Wildlife Fund’s page on Bornean orangutans to donate to the fund or adopt an orangutan.