The loss of habitat is a major threat to the survival of apes. Ape habitat, i.e. tropical forest, is lost through clearance for agriculture, urban development and logging, all involving the removal of the trees and other plants which apes need to find food and shelter. These activities reduce the space available for apes to live in but also reduce the quality of any remaining habitat, as it often fragmented and polluted by the infrastructure necessary to support these industries. More roads and people result in increased hunting pressure, disease and disturbance.
Ape populations isolated in fragmented forest pockets are at increased risk of extinction due to local catastrophes, such as disease outbreaks or freak weather, which can destroy the entire group with one event. In addition, small isolated populations are more likely to suffer genetic deterioration such as inbreeding, resulting in reduced fitness and loss of genetic variation reducing their long term ability to adapt to changing conditions.
In some cases managed forestry and reforestation projects further reduce habitat quality, by planting non-native species or monocultures of species with high commercial value to replace those removed. The resulting habitats are inappropriate and cannot sustain ape populations. Finally, deforestation contributes to climate change, the ramifications of which endanger all apes – including humans.
Them and us?
Agriculture and logging in ape habitats are carried out to meet the demands of local people and foreign consumers. When local human populations are small, their activities (gathering food and wood from the forest, growing crops and raising livestock) can be sustainable, i.e. they can live in harmony with the rainforest ecosystems and ape populations. However, larger groups of people using inefficient technologies (e.g. slash and burn agriculture, making charcoal) to sustain themselves have a destructive impact on ape habitats.
When agriculture and logging take place on a commercial scale, they have the potential to destroy ape habitat much more rapidly than small scale local forest exploitation. Products from commercial agriculture and logging, such as palm oil and teak furniture, are usually exported, providing much needed revenue to developing countries. Commercial agriculture has resulted in prime ape habitat being replaced by vast monocultures of plants such as oil palm and soya, which are used in the manufacture of a wide range of consumer products and biofuels. Large scale logging enables the manufacture of affordable (for western markets at least) wooden furniture and other products, whilst denuding huge tracts of primary forest.
