Maybe if the ecosytems weren't tampered with to begin with...the creatures who had their own checks and natural balances ...this would be a non-issue.

This is a small part of ecological changes where mankind has changed that balance. Tried to bring it back, as to the wolves, but when the rest of nature is out of balance re-introducing a native species just doesn't always goes as was planned.

Nature is much more careful in it's environment than it's "educated" human populas that needs to control the environment for their own benefit.