Most of the country is savanna grassland. There is little forest left; Burundi is one of the most eroded and deforested countries in all of tropical Africa. Of the remaining trees, the most common are eucalyptus, acacia, fig, and oil palms along the lake shores.
Wildlife was abundant before the region became agricultural. Still found are the elephant, hippopotamus, crocodile, wild boar, lion, antelope, and flying lemur, as well as such game birds as guinea fowl, partridge, duck, geese, quail, and snipe. Some 451 breeding bird species have been reported. The crowned crane is prevalent. As the region becomes more densely populated, some species are dwindling or disappearing.
In Lake Tanganyika there is a great variety of fish, including the Nile perch, freshwater sardines, and rare tropical specimens. Most of the 133 fish species in Lake Tanganyika are found nowhere else in the world.