"People used to think, 'Well, just keep everyone on the trail.' Before this study, that would have been a reasonable assumption," Merenlender said. "But now that we're showing this larger scale effect, we're going to have to shift our working paradigm on how we address land management."
To look at carnivore populations, Reed walked one to two miles in each park or preserve, picking up and bagging every carnivore dropping she saw. Because it's difficult to identify droppings visually, she used genetic analyses to determine each scat's owner.
Reed was surprised to find that coyotes and bobcats were avoiding parks with public access entirely, not just their trails. The parks she visited are small enough that the animals can't find a peaceful spot, Reed said.
Reed thinks the carnivores are leaving the parks for calmer neighboring areas. Her study didn't address the reason for their flight, but she thinks it likely that the mere presence of humans disturbs the animals. The noise of humans traipsing and chatting through parks, our smell or just the sight of us could frighten animals away from their homes, Reed said.
Between urban sprawl, agriculture and outdoor enthusiasts, coyotes, bobcats and foxes may be hard pressed to find undisturbed areas. Outdoor recreation is on the rise around the world, especially in natural areas surrounding large urban centers, such as in the San Francisco Bay Area. For example, the number of Americans day hikers jumped nearly 800 percent between 1960 and 2000, according to national surveys.
|Contact: Rachel Tompa|
University of California - Berkeley