Anthropogenic noise is one of the fastest growing and most ubiquitous types of environmental pollution and can impair acoustic communication in a variety of animals [1]. Recent research has shown that birds can adjust acoustic parameters of their sexual signals (songs) in noisy environments 2 and 3, yet we know little about other types of vocalizations. Anti-predator signals contain subtle information that is critical for avoiding predation 4 and 5, and failure to detect these calls 6 and 7 as a result of anthropogenic noise pollution could have large fitness consequences by negatively impacting survival. We investigated whether traffic noise impacts both the production and perception of avian alarm calls using a combination of lab and field experiments with great tits (Parus major), a songbird that frequently inhabits noise-polluted environments.

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