On top of it all, they are also seeing their homes destroyed by unscrupulous agribusiness companies – many foreign-owned – who are clearing vast tracts of rainforest throughout west and central Africa to make way for plantations producing palm oil, rubber and other commodities.
New evidence from Greenpeace Africa, publicized today, reveals that several projects in Cameroon are destroying and threatening ape habitat. Satellite images show that the Chinese-owned Hevea Sud rubber and palm oil project in the country's South region has already resulted in over 3,000 hectares of rainforest destroyed with many thousands more to come.
The concession borders the Dja Faunal reserve, a UNESCO world heritage site that is teeming with rare and endangered wildlife including the chimpanzee, the western lowland gorilla and the forest elephant. UNESCO asked for an inspection to be carried out some time ago to determine if the reserve had been impacted by the operations, but was refused by local authorities on "security grounds".
The destruction mirrors that caused by US-owned Herakles Farms for a palm oil project in the country's South West region. The deforestation carried out by the company – much of it illegally – destroyed vital corridors of forest used by chimpanzees and other mammals to move around the four protected areas between which the concession is sandwiched.
Indeed such projects and the resultant damage to habitat are being seen increasingly throughout the Congo Basin and throughout west and central Africa.
As Dr Joshua Linder, an assistant professor of anthropology at James Madison University, says: "Agro-industrial developments will soon emerge as a top threat to biodiversity in the African tropical forest zone. If proactive strategies to mitigate the effects of large-scale habitat conversion are not soon implemented, we can expect a rapid decline in African primate diversity."
One project that can yet be challenged is by local Cameroonian company Azur. A Greenpeace Africa investigation in December last year showed that they have their sights set on a concession covering dense natural forest close to the Ebo forest, a proposed national park. The area is home to chimpanzees and other highly endangered primates such as drills.
The Nigerian-Cameroon chimpanzee sub species is one of the most endangered primates in the world while the lesser known but no less magnificent drill is extremely rare, with more than 80% of the world's remaining population calling Cameroon home, in particular the south west of the country.
Greenpeace has written to Azur on several occasions, asking that they provide evidence to allay the growing environmental concerns over their project. There has been no response.
It is a stretch to believe that Cameroon's authorities are blissfully unaware of the controversy these type of projects are causing. The Hevea Sud concession even lies within the home district of the country's president Paul Biya.
More believable is that such controversy is willfully neglected, downplayed or ignored. While it is easy to understand how a chimpanzee or gorilla can fail to be consulted over the future of its home, less so is how a human community can.
Yet throughout Cameroon and the region in general there are numerous cases where projects are started and forests destroyed with little or no consultation with residents let alone their prior consent. Often they are paid a fraction of that their land is truly worth and many people are deprived of the forest and land that is not only their home but their livelihood.
Governments need to urgently develop a participatory land use planning process prior to the allocation of industrial concessions. Projects that are being developed without adequate community consultation and are located in areas of high ecological value should not be allowed to proceed and risk further social conflict and environmental damage.
If such measures are not introduced and effectively enforced then the forests, communities and wildlife of one the most biodiversity-rich regions on the entire planet will continue to be under threat.
Irene Wabiwa-Betoko is the forest campaign leader with Greenpeace Africa.