Like paparazzi snapping covert pictures of celebrities, a series of hidden cameras will soon be capturing images of red foxes, long-tailed weasels and white-tailed deer along the Appalachian Trail—the footpath that stretches 2,175 miles from Georgia to Maine. At night, the 50 heat- and motion-triggered cameras will photograph animals lured by scents used by trappers. Starting in April, for the second year, Smithsonian ecologist William McShea will oversee more than 100 volunteers, who will set up the cameras at predetermined points over a 575-mile stretch of the trail. McShea, who has been using the candid-camera technique in a bamboo forest in a continuing study in China since 2001, wants to see how this summer's images compare to the nearly 2,000 pictures taken on the trail last summer. "Coyotes, bobcats and black bear were surprisingly plentiful," he says. McShea, who hopes to eventually survey the entire trail, won't be able to determine the precise number of animals roaming the area (the same raccoon, for example, could be mugging for several shots). Results, however, could speak to the effects of human encroachment on animal habitats.