Nearly 50 years of conservation efforts have been unable to prevent orangutan numbers on Borneo from plummeting. The latest data published by a team from 38 international institutions, led by researchers of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, the German Centre for Integrative Biodiversity Research (iDiv) and
Liverpool John Moores University in Great Britain, suggests that between 1999 and 2015 the total number of Bornean orangutans was reduced by more than 100,000 animals.This result means two things. First, there were more orangutans on Borneo than previously estimated. Second, they are disappearing even faster than researchers had envisaged. The
most dramatic rates of decline in orangutan populations were found in deforested areas and in areas converted into agricultural land. Surprisingly however, the absolute number of orangutans that were lost was greatest in selectively logged and primary forests, where most orangutans occur.