How Wolves Change Rivers, narrated by the great leftwing writer George Monbiot. After wolves were reintroduced to Yellowstone, there were remarkable effects on the ecosystem across the board, all beneficial. Animal populations that were too high got reduced and populations that were too low increased. Birds came back in great numbers. So did beavers, mice, weasels, badgers, rabbits and even bears. Vegetation exploded, especially trees and bushes. And the rivers themselves were dramatically altered, changing from damaged streams to normal, healthy rivers.
This is called a trophic cascade, and the reintroduction of wolves to Yellowstone is one of the most striking examples of one seen in recent years. This cascade may not be reproducible in whole outside the park due to the effects of hunting, but I think you should see some beneficial changes in ecosystems with the reintroduction of wolves.
