Birds are great talkers and listeners, using vocalizations to communicate within their species. Whether for wooing mates, warning of predators, or chatting with offspring, birds excel at using their voices and ears to share meaningful information. All of which means they’re particularly vulnerable to noise disturbances.
Individual studies have documented the impacts of human noise on bird behavior and fitness, but now, a review study published in Proceedings of the Royal Society B paints a comprehensive picture of how noise pollution affects birds around the world. Researchers from the University of Michigan and California Polytechnic State University reviewed data from more than 150 studies encompassing six continents and 160 bird species. “Based on our assessment of this meta-analysis, we were able to generate a broader statement about trends we’re seeing,” said lead study author and conservation biologist Natalie Madden in a statement.
From published studies that explicitly tested the effects of anthropogenic noise on birds, Madden and her coauthors tallied changes in behaviors like aggression, foraging, communications, risk-taking, and habitat use. Fitness-related parameters, including growth, physiology, and reproduction, were also considered where available in the studies.
Read more: “Birds of a Feather Talk Together”
Overall, the literature review showed that human-generated noise—whether from traffic, construction, or other activities—had significant effects on birds' behavior and physiology. A bird species’ life history made a difference in how they responded to unnatural ambient noise. Cavity-nesting birds, for example, experienced negative impacts on growth compared to birds using open nests. City birds exhibited higher stress hormone levels than birds living in more tranquil habitats. And nearly every type of anthropogenic noise had a dampening effect on reproductive success.
The researchers assert that knowing the deleterious effects of human noise on birds should inspire us to buffer them from our noise pollution.
“So many of the things we’re facing with biodiversity loss just feel inexorable and massive in scale, but we know how to use different materials and how to put things up in different ways to block sound,” added Carter. “We just have to get enough awareness and interest in doing it.”
It would certainly give birds some peace and literal quiet. 
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Lead image: Chekalin Nikolai / Shutterstock
