Video: How wolves change rivers
When wolves were reintroduced to Yellowstone National Park in the United States after being absent nearly 70 years, the most remarkable trophic cascade occurred. The wolves have affected not just the surrounding living ecosystems, but the physical geography of the land itself. George Monbiot explains in this movie remix.
“When we try to pick out anything by itself, we find it hitched to everything else in the universe.” – John Muir