This video tells an awesome story of how introducing wolves to Yellowstone helped restore the ecosystem.
“When we try to pick out anything by itself, we find it hitched to everything else in the Universe.” - John Muir
When wolves were reintroduced to Yellowstone National Park in the United States after being absent nearly 70 years, the most remarkable “trophic cascade” occurred. What is a trophic cascade and how exactly do wolves change rivers? George Monbiot explains in this movie remix.