PhotoTo estimate changes in the size of Borneo’s orangutan population over time, researchers representing 38 international institutions compiled field surveys conducted between 1999 and 2015. They extrapolated the overall size of the island’s population from the number of orangutan nests found throughout the species’ range in Borneo. However, the World Wildlife Fund estimates that the remaining population of Borneo orangutans is much smaller, at around 105,000. To identify the likely causes of orangutan population losses, the researchers relied on maps of estimated land cover change on Borneo during the 16-year period. However, a much larger number of orangutans were lost in areas where there was less logging and deforestation.

Source: New York Times February 15, 2018 17:10 UTC