Researchers from the International Union for the Conservation of Nature (IUCN) have published a commentary claiming that the Indonesian government has its figures on orangutan populations wrong and the species is in much more trouble than the official numbers show.
Published in the journal Current Biology, the IUCN orangutan researchers based in Borneo say that the Indonesian government's claim that the orangutan population doubled from 2015 to 2016 is false.
They say it is "biologically impossible" for an orangutan population to double in a year.
In a State of Indonesia's Forest report released earlier this year by Indonesia's Ministry of Environment, the government said the population of orangutans was on the rise as a result of conservation efforts.
The authors of the commentary say recent research stated that the Bornean orangutan population has declined at least 25% over the past 10 years.
Lead author of the commentary, Erik Meijaard, is chair of the of IUCN Oil Palm Task Force. He has been working in conservation science in Indonesia for 15 years and told BuzzFeed News the government's estimates are incorrect as it doesn't employ comprehensive techniques for assessing numbers.
"When we estimate population size, we use very large databases from everything that's ever been done on orangutan population estimates," said Meijaard. These include helicopter surveys and extensive interviews with local populations.
The authors say the Indonesian government's statistics are skewed because they are monitoring sites where orangutans are being dropped off for reintroduction to the wild by conservation societies, and extrapolating those figures to represent all orangutan habitats.
Meijaard says the orangutan population will continue to decrease if the Indonesian government is planning conservation with the belief that "everything's okay" with their numbers.
Another study published in March this year suggested that 100,000 orangutans were wiped out by logging and hunting in Borneo from 1999 to 2015.
Meijaard notes that there may be a "vested political interest in steering the message a certain way" about orangutan population numbers, particularly when it comes to the palm oil industry and expanding plantations.
However Meijaard says the focus on the palm oil industry as the greatest threat to orangutans is a bit misguided. Research has indicated that the majority of orangutans are actually killed in heavy forest areas from hunting, and Meijaard believes nobody is adequately addressing it as a conservation issue.
"I don't want to slam the government, the government is trying," he said. "We've communicated the fact that we don't believe their statements, but the bottom line is they're wrong and we need a significant change in the way we go about orangutan conservation."