Forests, Fires, and Grasslands
The Impact of Elephants
on Their Habitats
It is not surprising that the largest terrestrial animals can make a tremendous impact on their habitats through their feeding activities. Imagine an elephant clan moving through a wooded savanna at an ecological density of 10 animals per square kilometer, each individual having a fresh forage requirement of up to 10% of its body weight each day. With an average individual weight of 1,800 kg, this elephant clan would consume 1,800 kg of vegetation each day from each square kilometer of habitat. Another 1,200 kg of vegetation would be wasted in the process. A 200-strong elephant clan would thus remove 60 tonnes of vegetation each day or 21,900 tonnes each year over a 20 km2 landscape. Even if such a high elephant density is seasonal and unlikely to be sustained over the year, an average density only a third the seasonal figure would still remove a considerable biomass of woody vegetation over large landscapes.
Now, if most of the forage removed by elephants were to be grass or other herbs, there probably would not be much concern. After all, there seems to be no shortage of grass in the African savannas for elephants and other herbivores. Elephants, however, also feed on shrubs and trees, breaking branches, stripping bark, and uprooting huge trees. When a centuries-old stately baobab is reduced to pulp by elephants trying to get at its succulent pith or a fever tree (a major attraction for tourists, who wish to see lions under its shade or a leopard perched on a branch) is pushed over by a bull elephant for just one