The answer seemed to be a resurgence of willow, the riparian shrub that is the beaver’s preferred food. And why was the willow coming back? Smith was still trying to figure that out, but he knew the answer almost certainly had something to do with wolves. As their numbers grew after reintroduction, elk numbers had of course declined, but—just as important—their behavior had changed as well. No longer free to congregate at their leisure along stream banks, elk were spending less time browsing on willow, which left plenty for the beavers.
