By Basten Gokkon
The world lost nearly 150,000 orangutans from the island of Borneo in the past 16 years due to habitat loss and killing, and is on track to lose another 45,000 by 2050, according to a new paper in the journal Current Biology.
The study, published Feb. 15, observed 36,555 orangutan nests across Borneo, an island that is shared between Indonesia, Malaysia and Brunei, between 1999 and 2015. During that period, the researchers reported a steep decline in the number of nests they encountered over a given distance: the encounter rate more than halved from 22.5 nests per kilometer (about 36 per mile) to 10.1 nests per kilometer. That decline, they calculate, represents an estimated loss of 148,500 individual Bornean orangutans (Pongo pygmaeus).