In the Lake Victoria region and the western highlands, forest covering has been replaced by elephant grass and forest remnants because of human incursions. The medium-elevation forests contain a rich variety of species. Fauna Lions and leopards are now present mainly in animal preserves and national parks, but they are occasionally seen outside these places. Hippopotamuses and crocodiles inhabit most lakes and rivers, although the latter are not found in Lakes Edward and George. Mountain gorillas, chimpanzees, and small forest elephants appear only in the extreme west.
Insects are a significant element in the biological environment.
Much of southern Uganda has been deforested, but a significant portion of the country's area has been placed in its 10 national parks. Queen Elizabeth National Park is about half the size of Murchison Falls and is in the Lake Edward-Lake George basin. Bwindi Impenetrable Forest, a World Heritage Site, contains about half of the world's population of endangered mountain gorillas, and Mgahinga Gorilla National Park is also home to this rare mammal.