Bringing Back the Wolves: How a Predator Restored an Ecosystem

Bringing Back the Wolves: How a Predator Restored an Ecosystem — page 5
ber TAMING THE WILD In the late 1800s the American government offered money a bounty to encourage people to hunt top predators cougars grizzly bears and wolves The goal was to tame the West the heart of cattle ranching and rid the landscape of all threats to livestock The result hunters killed so many wolves that by 1926 no wolf packs were left in Yellowstone National Park Wolves are a keystone species And the absence of a keystone species affects the ecosystem both directly and indirectly In Yellowstone wolves directly affected elk by eating them But they indirectly affected many other living things too aspen trees coyotes songbirds and beetles to name just a few And they also affected non living things such as the soil and the stream bank A Missing Link Wolves are top or apex predators When such an important member of an ecosystem goes missing many other living things are indirectly affected causing a chain reaction of events This is called a trophic cascade A trophic cascade works in the opposite direction too Reinstating the missing link can also cause a chain reaction