The Birds and the Trees
Plant a tree, improve your soundscaping.
Posted July 4, 2011
One study in the Journal of the Acoustical Society of America looked at the benefits of adding natural sounds to traffic noise. The idea was that it's not always practical to get rid of unwanted noise, but adding wanted sounds may make mask the noise or distract attention from it. The results supported this idea, showing that soundscapes were rated as more pleasant when the sound of passing traffic was combined with bird sounds.
In a second study published in Environmental Management, Korean college students viewed pictures of hikers at a mountain park while listening to various sounds. Bird sounds decreased perceptions of crowding and increased tolerance for seeing other people on the trail. Conversely, airplane or truck sounds had the opposite effect.
Bird calls and songs can be lovely to listen to, but they also serve a utilitarian purpose. Whether attracting mates, defending territory, or signaling danger, birds communicate with each other acoustically. Bird sounds engage the human brain as well, conveying information about our surroundings. They foster a connection with nature, which research shows may provoke effortless attention, restore alertness, reduce stress, decrease hostility, and promote a sense of well-being.
In addition, there's another way that bird sounds may enhance human health. In the spring, songbirds sing loudest around daybreak, a phenomenon called the dawn chorus. It's thought that the dawn chorus allows male birds to proclaim their territory and serenade the females before predators are out. But this symphony of birdsong also provides humans with a cue about time of day.
Several studies in birds and nonhuman primates have shown that their biological clocks are sensitive to auditory stimuli. Some evidence suggests that birdsong may affect human circadian rhythms as well. Specifically, it may be one of the external cues that help synchronize the body's internal clock to the 24-hour day. This synchronization, in turn, may have positive effects on sleep and mood.
The best way to attract feathered friends to your neighborhood is by planting a tree. Native trees make ideal nesting spots for local bird species, and they also offer protective cover from predators. Plus, trees provide nuts, seeds, and fruit for food.
To draw particular types of birds, choose one of the tree species they prefer. For example, Eastern red cedars roll out the welcome mat for the American robin, southern magnolias for the wood thrush, and California wax myrtle for the yellow-rumped warbler. For popular regional suggestions, visit the Audubon Society online.
Like graceful birds and melodious birdsongs, green leaves and rustling branches have a deep aesthetic appeal. They're a pleasant diversion from the stark lines and harsh noises of the manmade environment. And they're a revitalizing reminder that all of us - even confirmed urban dwellers - are still part of the natural world.