Traffic noise inhibits inhibitory control in wild-caught songbirds.

Anthropogenic noise is ubiquitous across environments and can have negative effects on animals, ranging from physiology to community structure. Recent work with captive-bred zebra finches demonstrated that traffic noise also affects cognitive performance. We examined whether these results extend to animals that have experienced noise in the wild. We collected black-capped chickadees from areas frequently exposed to road traffic noise and tested them on a detour reaching task, a commonly used measure of inhibitory control. Those chickadees exposed to traffic noise playback had much lower performance on the task than control birds, indicating that noise negatively impacts inhibitory control. These data corroborate previous findings in lab-reared zebra finches. Furthermore, these results suggest that prior experience with traffic noise is not sufficient for animals to habituate to noise and overcome its negative effects on cognitive performance. Instead, noise-induced cognitive effects might have broad impacts on animal species living in noise-polluted habitats.

Traffic noise inhibits cognitive performance in a songbird.

Noise pollution is commonly associated with human environments and mounting evidence indicates that noise has a variety of negative effects on wildlife. Noise has also been linked to cognitive impairment in humans and because many animals use cognitively intensive processes to overcome environmental challenges, noise pollution has the potential to interfere with cognitive function in animals living in urban areas or near roads. We experimentally examined how road traffic noise impacts avian cognitive performance by testing adult zebra finches (Taeniopygia guttata) on a battery of foraging tasks in the presence or absence of traffic noise playback. Here, we show that traffic noise reduces cognitive performance, including inhibitory control, motor learning, spatial memory and social learning, but not associative colour learning. This study demonstrates a novel mechanism through which anthropogenic noise can impact animals, namely through cognitive interference, and suggests that noise pollution may have previously unconsidered consequences for animals.