Four score and, oh, say, half a score years ago, Yellowstone National Park lost its grey wolves, and with them a major cog in Nature's biological wheel. No wolves meant more elk meant less plant life, which in time meant trouble for aspen trees. (No trouble, though, for Scooter Libby's cryptic poetry.)
But scientists reintroduced wolves to Yellowstone in the mid-1990s, and a new paper in Biological Conservation reports that order is being restored. The elk, fearful of becoming Wolf Fare, avoid munching low brush in certain areas of the park. As a result, many young aspens have grown too tall--reaching seven feet--for elk to eat.
I spoke with one of the study's authors, William J. Ripple of Oregon State University, for a recent Smithsonian.com story about the displacement of cougars in Zion National Park. The cougars are essentially to Zion what the wolves are to Yellowstone.
So, a score years or so from now, the heavy tourist traffic at Zion that's causing the cougars to move might impact the region's cottonwood trees. Unless, of course, we
feed teach the tourists to about the wolves.