Noise and Light Pollution Alters Ecologies

Human noise and light are creating fundamental changes in ecological communities -- changing the density, diversity and dependencies of bird species that are biological barometers of the natural world.

But peace can be restored to the wilderness by enlisting technologies that create a darker and more silent world, a panel of experts said Monday in San Jose on the final day of the annual meeting of the American Association for the Advancement of Science.

"Noise levels and light levels both can be improved as soon as we decide to throw the switch," using more electric cars and LED lighting, said Kurt M. Fristrup, of the National Park Service's Division of Natural Sounds and Night Skies, in Fort Collins, Colorado.

Birds are long-standing indicators of a habitat's health -- the so-called "canaries in the coal mines" that document subtle shifts in the natural world. Noise seems to change where they breed and how they feed; artificial light alters their inner clocks, altering when they wake up and nest.

But chronic stimulation is not just hard on birds, but also humans, Derrick Taff of Pennsylvania State University.

"Natural sounds and dark night skies ... are essential for quality human experiences," helping us restore and recover, he said.

Specifically, the scientists reported that:

-- Noise causes an overall decline in species richness, according to a study of New Mexico gas extraction sites where loud compressors were surrounded by silent woodlands. The study by Clinton Francis of California Polytechnic State University in San Luis Obispo found that 32 bird species nested in the quiet areas. Only 21 species nested in noisy sites.

-- Some bird species, such as Western scrub jays, were 32 percent more common in quiet areas. Other species, such as black-headed grosbeak, also fled noise. They sing at lower frequencies and, according to Francis, industrial rumbling may conceal their...