Helen Fields and Alanna Mitchell
PUBLISHED AUGUST 28, 2014
WAYNESBORO, Virginia—Standing in the woods along the South River, Kelly Hallinger held the microphone up to capture the cacophony of songs, one at a time: the urgent, effervescent voice of the house wren; the teakettle whistle of the Carolina wren; and the sharp, shrill notes of the song sparrow.
It was the summer after her freshman year at the College of William and Mary in Williamsburg, and Hallinger was working with her professor, ecologistDan Cristol, to investigate the effects of mercury left behind by a factory. Over and over she recorded birdsong, visiting various sites in the woods and along the shore, some polluted, some unpolluted.
When she got back to Williamsburg with her tape recorder, Hallinger sorted through the hours of bird songs. She turned them into digital files in the computer, then analyzed them. The differences were striking: The wrens and sparrows along the contaminated South River were singing simpler, shorter, lower-pitched songs.