Pringle notes that elephants really shake up the savanna landscape. The level of disturbance from a feeding herd is almost akin to that of a tornado touching down; trees and shrubs are splintered, cracked, and fissured and large branches are strewn all over the ground.
The ripped up trees are like labyrinths compared to the pristine trees, which helps boost lizard densities, says Pringle. This may be because the twisted crevices in the elephant-damaged trees provide shelter from predators and the harsh arid environment, or because they provide suitable spots for female lizards to lay eggs.
A better understanding of the elephants influence on their ecosystem is a particularly pressing need in this region. There are concerns in many parts of Africa that poaching may wipe out the large animals on lands where they are not strictly protected. Elephants, however, eat a tremendous amount, and their eating habits can be especially destructive in smaller tracts of land. Since they have no real natural predators besides humans, they can sometimes eat themselves out of house and home in the areas where they are protected from hunters.
Because of these management dilemmas, finding an optimum number of elephants for any given refuge or wildlife area has become a hot topic. By gaining a better understanding of ecosystem engineering and the effects that large herbivores have on other species, researchers may gain more insight into how the entire savanna ecosystem works.
If you have no elephants, says Pringle, then youre missing this powerful source of disturbance, since their activities can provide other species with a chance to thrive. On the other hand, if you have too many elephants, then they can actually suppress
|Contact: Nadine Lymn|
Ecological Society of America