Animal Landscapers

How creatures alter geology

- Cody Cottier

Kenyan termite mound

EARTH'S SURFACE IS A WORK forever in progress. Boulders tumble down mountain slopes raised by colliding tectonic plates.

Glaciers grind the boulders into dust.

Wind, rain and rivers carry that dust to the sea, where it becomes sediment. These are among the traditional ways landscapes are known to change. But new research suggests there's a mighty force of nature missing from this picture: animals.

In a study published in the Proceedings of the National Academy of Sciences USA, researchers estimate that wild freshwater and terrestrial species, ranging from salmon to elephants, expend 76,000 gigajoules of energy to alter the land around them every year-the equivalent of thousands of extreme floods.