According to a current evaluation, the number of great apes on Borneo has decreased by almost 150,000 over the past decade and a half. It is estimated that there are now only between 50,000 and 100,000 of these animals.Orangutans are critically endangered. The fact that orangutans on Borneo are endangered is certainly not new, but "critically endangered" - i.e. acutely endangered - they did not seem to be so far. According to new studies, however, approximately 82 percent of Borneo orangutans will have disappeared between 1950 and 2025.