“Ah, listen to those wonderful sounds of nature,” you say as you step out onto your porch in the morning — only to have your neighbor fire up the leaf blower or the lawn mower. Sure, it’s irritating to us, but does it matter to the birds?

New studies are showing that the answer is indeed an emphatic “Yes!”

A new study released in September used an innovative experimental design in which speakers were placed in a roadless area in Idaho. The speakers played the recorded sounds of passing cars. The researchers used mist nets to capture migrant birds at the location and at a nearby location where no sounds were broadcast. They found that not only was the total number of birds reduced in the area where the road sounds were played, but that the body condition was worse for birds that stayed in the noisy area. The researchers wanted to know why this might be and so conducted another interesting experiment to find out. They captured some migrant white-crowned sparrows and let them feed in a large enclosed area, sometimes in silence, sometimes with traffic noise. They videotaped their behavior (see videos at  http://intl.pnas.org/content/112/39/12105.abstract?tab=ds). The research showed that birds experiencing the noisy acoustic environment spent more time looking around vigilantly for possible danger while those experiencing quiet moved around and fed more vigorously. The researchers surmised that in the real world, birds near roads or in other noisy places must generally spend less time feeding and more time watching out for danger.

This study is one of many that have shown that noise alone from roads or industrial installations can decrease abundance of many bird species. During the breeding season, there’s the added complication for singing birds of the fact that it may be hard for their songs to be heard over human-caused noises. Some research has suggested that birds with lower frequency calls may be especially impacted, since the sounds of cars and engines and pumps are generally also low frequency sounds. We have written in this column before about how the low-frequency thumps of a drumming ruffed grouse sound like a far-off, old-fashioned tractor engine starting up; presumably, the sounds of a real engine could probably mask the sound of a male ruffed grouse spending lots of energy to attract females.

Roads and traffic are a necessary part of modern infrastructure and our existence, and we can’t do much to change that. But these studies do point out the critical importance of maintaining large areas that are as free of roads and industrial noises as possible so that birds (and other creatures, too) have places that they can have their best chances of raising young and feeding during migration. The Boothbay Region Land Trust preserves in our local area are, of course, one example of these kinds of natural sound oases in our area. Baxter State Park and the efforts to establish a national park along its eastern border are examples at much larger scales of the kinds of places we need that can allow birds to flourish in areas where they, and you, can enjoy the sounds of nature all year round.

Jeffrey V. Wells, Ph.D., is a Fellow of the Cornell Lab of Ornithology. Dr. Wells is one of the nation's leading bird experts and conservation biologists and author of the Birder’s Conservation Handbook. His grandfather, the late John Chase, was a columnist for the Boothbay Register for many years. Allison Childs Wells, formerly of the Cornell Lab of Ornithology, is a senior director at the Natural Resources Council of Maine, a nonprofit membership organization working statewide to protect Maine’s environment. Both are widely published natural history writers and are the authors of the book, Maine’s Favorite Birds.