Cascade effects in Yellowstone

This fascinating NYT article on the cascade effect of the Yellowstone wolf introduction may prepare our imaginations in just a small way for the effects if "ReWilding" starts. The change in the plant ecology and species composition of the Plains and Southwest alone is going to be amazing.

"Where willows and cottonwoods have returned, they stabilize the banks of streams and provide shade, which lowers the water temperature and makes the habitat better for trout, resulting in more and bigger fish. Songbirds like the yellow warbler and Lincoln sparrow have increased where new vegetation stands are thriving.

"Willow and aspen, food for beaver, have brought them back to the streams and rivers on the northern range. In 1996, there was one beaver dam on the northern range; now there are 10.

"The number of wolves has also greatly increased the amount of meat on the ground to the benefit of other species.

Grizzlies and coyotes rarely kill adult elk, but each pack of wolves kills an elk every two or three days. After they eat their fill, other carnivores take over the carcass. Opportunistic scavengers like magpies and ravens make a living on the carcasses.

"The number of coyotes, on the other hand, has fallen by half. Numbers of their prey - voles, mice and other rodents - have grown. And that, in turn bolsters the populations of red foxes and the raptors."

I have ordered Paul Martin's new book Twilight of the Mammoths, on the ReWilding project, and will review it here soon.