Genetic Evidence Shows Colonialists Pushed Orangutans To Brink Of Extinction

The population has declined up to one hundred fold since the late 19th Century, coinciding with the arrival of colonial powers on the island of Borneo and accelerated timber extraction. The research is among the first to link species decline with colonial deforestation, as opposed to when humans first appeared in the region.

"This is the first time that an alarming and recent human related decline of a great ape population has been demonstrated using genetic data," said Dr Benoît Goossens, Cardiff School of Biosciences.

"The research used a new, innovative analysis that meant we could distinguish between population decline that happened thousands of years ago and much more recently".

The team of researchers sampled the faeces from two hundred orangutans in the Kinabatangan Wildlife Sanctuary in Sabah, northern Borneo and DNA profiling was used to discover the most likely history of the population that would give rise to their genetic profiles.

"It is clear that the remaining population of orangutans in Sabah is a very small fraction of what originally existed, and more importantly, if the decline continues at the same speed, the population will be extinct within a few decades," said Dr Goossens.

Normally the genetic effects of recent events such as colonial deforestation would be obscured by ancient demographic events. However, humans have so devastated orangutan populations that the genetic signature of the recent bottleneck may have overshadowed any previous population fluctuations.

"The results of the study underscores the need to act now to protect the long term survival of the species. The animals still possess enough genetic diversity to stabilise if immediate action is taken to halt further decline", said Professor Michael Bruford, Cardiff School of Biosciences, who led the study.

The Cardiff University team is working with its partners in Sabah and the local government to set up an effective conservation programme that will identify mechanisms for local and regional economic development that includes the protection of orangutan habitat.

The groundbreaking findings are published in the top ranking international biology journal, PLoS Biology, and have attracted widespread media coverage, including in The Western Mail, The Times, The Guardian, and BBC.

The study was carried out by Cardiff School of Biosciences, together with the Sabah Wildlife Department, the Kinabatangan orangutan Conservation Project and the Univesiti Malaysia, Sabah. The research was funded by the Department for Environment, Food and Rural Affair’s Darwin Initiative.