Herd of Hybrid Bison on Rampage in Grand Canyon

There's a menace on the loose in the Grand Canyon, and it is very large, and very hairy. A herd of between 350 and 450 hybrid bison are running amok in the area, federal and state park officials revealed at a news conference yesterday, announcing a series of public meetings to decide what to do about them. The animals have cleared whole meadows of vegetation, disturbed spotted owl habitats, left ruts in wetlands, defecated in lakes, and even knocked down walls of American Indian cliff dwellings, the AP reports.

Rancher Charles "Buffalo" Jones created this breed of cow-bison hybrids in 1906, calling them "cattalo" or "beefalo," National Parks Traveler explains. It didn't really work—today they have just 10% cow DNA and no discernible cow features. Arizona had kept the population in check through hunting, but hunting is illegal in national parks, including the Canyon. The Park Service is thus hoping to evict them onto Forest Service land where they'd be fair game again, despite some calls to leave them for study. (More Grand Canyon stories.)