Prairie Dogs Driven Underground by Traffic Noise

Prairie dogs, used to their serene grassland terrain, are driven underground when exposed to traffic noise, according to a new study.

Other researchers have studied the effects of noise pollution on animals - like marine creatures such as sea hares, for instance, as Nature World News recently reported - but rarely have they focused on how it affects the behavior of land animals.

A group of Colorado biologists took a recording of heavy traffic along Interstate 25 (about 5,600 vehicles-per-hour), and played the audio back in the presence of prairie dogs. This repeated cacophony alarmed the critters, who took to hiding in their burrows from the noise.

From May to August 2013, the research team visited each colony 10 times and monitored prairie dogs' response to these highway sounds.

When they played an hour-long recording at remote burrows - nearly a mile away from the nearest road - "the number of prairie dogs aboveground declined by 21 percent, the proportion of individuals foraging was reduced by 18 percent, vigilance [looking about for predators] increased by 48 percent, while social and resting behavior was halved" the scientists wrote in the journal Animal Behaviour.

Though it's to be expected that the animals did not prefer the noise, lead researcher Graeme Shannon, a postdoctoral behavioral ecologist at Colorado State University in Fort Collins, was surprised that the prairie dogs did not get used to the constant rumble of cars and trucks over time, an effect known as habituation.

"I thought they would start habituating to it, or they would realize that it wasn't a threat," Shannon told Live Science. "But that didn't happen in the three months."

"The effects of noise might be more insidious than we may have realized," he added.

More than 80 percent of land in the continental United States is within 1 mile of a road, according to a 2003 study published in the journal Frontiers in Ecology and the Environment. This goes to show that noise pollution may affect more land animals than previously thought.

The findings are important for officials who manage noise pollution, according to Clinton Francis, assistant professor of ecology at California Polytechnic State University who was not involved in the study.