The biodiversity of the Congo rainforests is unique. The forests are home to more than 400 mammal species, more than 1,000 bird species and at least 10,000 plant species.
But in the savannas of the lower reaches of the Congo River, the formerly rich fauna is almost extinct. The civil war and bushmeat hunting have greatly reduced the number of animals. Now the environmental organization WWF is sending biologists there to find out just how much biomass and biodiversity still exists in the Congo basin. Every sign of life, including hoofprints, is recorded. Data are also collected from the air.