Skeletal remains in the snow of a deer killed by a wolf in Idaho.

How Wolves Change Rivers

Incredible video about how the wolves, re-introduced into Yellowstone National Park in 1995, have started a trophic cascade – an ecological process that starts at the top of the food chain and tumbles all the way down to the bottom – and how this trophic cascade has actually altered the rivers in the park.  It is all good news and time well spent to view the video.