Science News reports: Even in the wilderness, humans are making a ruckus.

In 63 percent of America’s protected places — including parks, monuments and designated wilderness areas — sounds made by human activity are doubling the volume of background noise. And in 21 percent of protected places, this racket can make things 10 times noisier.

Enough clatter from cars, planes and suburban sprawl is seeping into wild places to diminish animals’ ability to hear mating calls and approaching predators, a team of researchers based in Colorado reports in the May 5 Science. Human noise doesn’t always have to be loud to override natural sounds, though. Some places are so quiet to begin with that even the smallest amount of human noise can dominate, the researchers found.

“The world is changing, and protected areas are getting louder — the last strongholds of diversity,” says Jesse Barber, an ecologist at Boise State University in Idaho. Studies like this one that show the impact of human-related noise across the entire country instead of in a single park are important, he says, because “this is the scale at which conservation occurs.” [Continue reading…]