The Consequences of Noise and Air Pollution on Bird Reproduction

by Saarang Kashyap

The impacts of noise and light pollution on the health of bird populations has been largely overlooked. A new study by biologists at California Polytechnic State University takes a huge step forward in quantifying the negative effects of noise and light pollution on bird nesting habits and success.

Researchers looked at a massive collection of data sets — including those collected by citizen scientists through the NestWatch Program — to assess how light and noise affected the reproductive success of 58,506 nests from 142 species across North America. The team considered several factors for each nest, including the time of year breeding occurred and whether at least one chick fledged from the nest.

The biologists found that light pollution causes birds to begin nesting up to a month earlier than normal in open environments such as grasslands and wetlands, and 18 days earlier in forested environments. The consequence could be a mismatch in timing — hungry chicks may hatch before their food is available. When considering noise pollution, results showed that birds living in forested environments tend to be more sensitive to noise than birds in open environments.  Noise pollution delayed nesting for birds whose songs are at a lower frequency as they were more difficult to hear through low-frequency human noise.

As NASA states, these findings suggest two conclusions about birds’ responses to climate change. First, at least temporarily, birds in brighter conditions are tracking climate change slightly better than those living in dark areas. Second, when considering noise pollution, results showed that birds that live in forested environments tend to be more sensitive to noise than birds in open environments.

The study is the first step toward a larger goal of developing a sensitivity index for all North American birds. The index would allow managers and conservationists to cross-reference multiple physical traits for one species to assess how factors such as light and noise pollution would affect each species. Developers and land managers can then use this data to see how implementations of new plans affect avian wildlife.

Image: https://justbirding.com/wp-content/uploads/2019/02/cool-birds-european-bee-eater-couple-Merops-apiaster.jpg