Habitat loss is one of the key factors for the decline in orang-utan numbers. The habitats of orang-utans are being cleared to make way for the establishment of revenue-generating industries. As seen on the graph below, the amount of forest cover has been reduced since the 1980s.
The picture below shows the deforestation trend in Borneo and the changes in the distribution of the orang-utans in Borneo over the years.
Habitat loss consist of 3 human activities and they are: