Who is taking down the precious Japanese cherry trees in the Tidal Basin, during Cherry Blossom Festival? Not extremists. In the city named for the Father of Our Country, the National Park Service cannot tell a lie: A beaver is doing it.

Like buzzard hawks circling the Jones Falls Expressway, deer chewing up parts of Roland Park or the coyote that invaded New York's Central Park, beaver have reacted to loss of habitat by reinvading what humans took away -- notably the water by the Jefferson Memorial in the nation's capital.

The official version, that this is the work of one beaver working alone, is much disputed. It is credited with teeth marks to 30 trees in three years (1 percent of the total), and the felling of nine in less than a week. Yet no dam or lodge appears. Whenever the beast takes down a tree, the Park Service carts it away, dooming another.

No wonder the U.S. government is hapless before its foes. With one of the nation's most cherished parks coming down before its eyes, the National Park Service remembers its priority: Save the animal.