Yellowstone National Park
Starting in 1914, the U.S. Congress gave money to people for "destroying wolves, prairie dogs, and other animals" that harmed agriculture or livestock on public lands. After the wolves were gone from Yellowstone, the coyote became the park's top canine predator. However, the coyote cannot easily kill large animals. The result was a big increase in hurt and sick megafauna (mainly meaning bison).