Elephants (and extinct relatives) as earth-movers and ecosystem engineers
Modern African elephants affect habitats and ecosystems in significant ways. They push over trees to feed on upper branches and often peel large sections of bark to eat. These destructive habits sometimes transform woody vegetation into grasslands. Elephant trail systems may be used and re-used for centuries, creating incised features that extend for many kilometers on migration routes. Elephants digging in search of water or mineral sediments may remove several cubic meters of sediments in each excavation. Wallowing elephants may remove up to a cubic meter of pond sediments each time they visit water sources. Elephant dung accumulations on frequented land surfaces may be over 2 kg per square meter. Elephant trampling, digging, and dust-bathing may reverse stratigraphy at archeological localities. This paper summarizes these types of effects on biotic, geomorphic, and paleontological features in modern-day landscapes, and also describes several fossil sites that indicate extinct proboscideans had very similar effects, such as major sediment disturbances.