We live in a world filled with noise. Noise can affect the physical and mental health of humans and animals. For birds, noise is a chronic and inescapable source of stress.
A study conducted on tree swallows found that ongoing traffic noise disrupts stress hormone levels in nestlings and adult females. Traffic noise may also reduce the ability of adult females to respond to stressful situations, which could result in poor health and reduced survival. A higher stress response often allows animals to escape life-threatening circumstances. Unfortunately, the detrimental impact of noise on the stress levels of adult females only worsens over time. Similarly, traffic noise negatively impacts the health, development, and growth of nestlings, which may decrease their chances of survival. Another tree swallow study found that females nesting in noisy areas lay fewer eggs, causing a reduction in reproductive success. Both studies concluded that exposure to traffic noise could have devastating effects on the local population of birds.
Noise pollution not only has negative implications for birds like tree swallows but for humans as well. Humans benefit greatly from tree swallows. They eat many insects that humans consider pests such as ants, flies, spiders, crickets, wasps, mayflies, and caddisflies. Since these birds help control the pest population, noise pollution impacting the birds’ stress levels and reproductive success could have consequences for humans as well.
In another study, researchers created a phantom road, a roadless area with various speakers applying traffic noise, to test the impact of noise on a community of songbirds during autumn migration. About one-third of the songbird community avoided the road. The birds that stayed despite the noise experienced a decline in their health. As shown by the study, noise pollution diminishes the quality of habitats because fewer birds opt to stay in noisy habitats, and, as a result, those habitats become less supportive of the bird community. Habitat degradation results in fewer birds in the area, which could have dire consequences for the ecosystem. Songbirds play an integral role in the ecosystem and provide essential services for humans. They consume insects, helping to control the pest population and prevent pest-induced damage to trees and crops. Songbirds also disperse seeds and pollinate plants. Without them, we would have fewer flowers, plants, and trees.
Noise pollution is more prevalent in urban areas and disproportionately affects communities of color and low-income communities. Long-term effects of noise exposure include lower birth weight, cardiovascular disease, diabetes, and high blood pressure. According to research conducted by the University of Exeter and the British Trust for Ornithology, people in crowded urban settings, particularly poorer areas, see more “nuisance” birds, including gulls, magpies, and pigeons, and fewer songbirds.
Songbirds have a positive impact on human well-being. People living in areas with more birds, trees, and shrubs are less likely to experience stress, anxiety, and depression. Listening to birdsongs lifts people’s spirits. Bird experts believe that people find birdsong reassuring and relaxing because, for thousands of years, people have learned that they are safe when birds sing. When birds stop singing, people worry. Therefore, people living in noisy areas not only suffer from the direct harmful effects of noise pollution on their health and well-being but also suffer indirectly from the negative impacts that noise pollution has on birds.
Kyra Bonta is a senior at St. Mary’s Academy in Portland, Oregon. She enjoys birdwatching with her family and likes to observe hummingbirds peacefully feed from, and sometimes aggressively battle over, the salvia and fuchsia on her deck. She previously created an interpretive ballet piece on noise pollution. In her free time, she runs a nonprofit, Ballet in Color, mentoring and teaching young black ballerinas.