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Research / Discovery

Traffic noise affects prairie dogs

August 14, 2014

The cost of living near a freeway may be on the rise, for wildlife.

When prairie dogs hear traffic, they spend more time on high alert for predators rather than foraging for food. Photo credit Graeme Shannon.Expanding roadways and traffic world-wide is a key contributor to habitat fragmentation, and researchers at Colorado State University have discovered that anthropogenic noise from road traffic alters the foraging and vigilance behavior of a free-ranging mammal.

Crucial component

Prairie dogs are a crucial component of the American prairie and necessary for a healthy ecosystem, but are commonly overlooked from a conservation perspective. They are considered highly tolerant of non-lethal human activities, but have suffered huge declines due to habitat loss, poisoning, shooting and disease outbreaks. The prairie dog is a keystone species whose survival is crucial for other prairie species, like the endangered black-footed ferret.

The team conducted research on rural prairie dog populations in Colorado, and utilized audio playback experiments to simulate colony exposure to highway traffic noise and isolate the impacts. The study was published in Animal Behaviour, and provides the first experimental evidence that noise from road traffic can degrade habitat and impact the behavior of this keystone species.

Prairie dog Substantial effects

“Over the next 40 years, road travel is set to double worldwide. The effects on biodiversity from this expansion are likely to be substantial, and it is crucial that we are able to quantify the behavioral and fitness costs of different road-related disturbance factors, such as noise, in order to design and implement effective mitigation measures,” said Graeme Shannon, a postdoctoral wildlife ecologist in CSU’s Warner College of Natural Resources and the paper’s lead author.

The study found that the exposure to noise causes behaviors similar to those that would be experienced with elevated risk of predation, for example, reduced foraging and increased alertness. However, there is also the possibility that vocal signals used to alert other prairie dogs to approaching threats may be masked by the traffic noise. “It’s very similar to when we try to conduct a conversation alongside a busy street - it can be difficult to hear what the other person is saying,” Shannon explained.

Prairie dogs make good subject animals because they live in high density colonies and are cognitively advanced. They are social creatures that use complex vocal communication, so the findings could lead to future discoveries with other social species.

Global implications

“The fact that we found significant changes in their behavior has implications for this species and also more disturbance sensitive animals that may be ultimately lost from habitats that get too noisy,” Shannon said. “Our findings have global implications as road traffic and construction increases worldwide.”