The reintroduction of wolves to Yellowstone National Park had a positive impact on the beaver population. With the presence of wolves, the elk population decreased as they were now being predated upon by wolves. This decrease in elk numbers allowed for the vegetation along rivers and streams to recover and grow back, providing better habitat for beavers to thrive. As a result, the beaver population in Yellowstone increased, as they were able to find more food and suitable habitat for building their dams and lodges. This in turn had a positive cascading effect on the ecosystem, benefitting other species such as fish, birds, and insects.
