WWF in collaboration with the respective country ministries in charge of wildlife and various partners conducted the censuses between 2014 and 2016. The inventories were carried out in key protected areas (representing 20 per cent of the survey area) and surrounding zones (logging concessions, hunting areas and other land use types) in Cameroon, the Republic of Congo, the Central African Republic and Gabon. The censuses focused on forest elephants, great apes (chimpanzees and gorillas) and additional data were collected on levels of human activities.