When Elizabeth Derryberry saw how dramatically traffic decreased during shutdowns to limit the spread of COVID-19, the University of Knoxville, Tennessee, professor wondered how the reduced noise might affect bird song.
Derryberry, an associate professor in the Department of Ecology and Evolutionary Biology, studies the white-crowned sparrow, a songbird common on the West Coast.
“I became interested in these sparrows because they are one of the few songbirds for which we have recordings over more than 30 years. There aren’t many behaviors with historical records like that,” Derryberry said. “I’ve remained interested in them because they are so good at living near people. They are found all along the West Coast in cities and people’s backyards and are truly an urban survivor.”
In 2012, she began studying how noise pollution affects the sparrows with David Luther, an assistant professor of biology at George Mason University. Their research collected recordings from urban and rural sites across the San Francisco Bay area from April through June 2016.
This past spring, after Derryberry saw photos of the Golden Gate Bridge nearly empty of traffic due to the pandemic shutdown, it piqued her curiosity. Would people be able to hear more songbirds?
A postdoctoral fellow at California Polytechnic State University, San Luis Obispo, collected new recordings from the same San Francisco areas in April and May 2020. Then Derryberry collaborated with two UT colleagues—research scientist and data analyst Graham Derryberry and associate professor Michael Blum—as well as a team from California Polytechnic State University and George Mason University to analyze the results.
The researchers’ findings revealed a drastic difference in just a matter of weeks after the start of the shutdown. Half a century of urban noise pollution had been erased. Records from the Golden Gate Bridge showed traffic levels compared to 1954, and dense urban areas of San Francisco were no noisier than the rural surrounding county.
Although white-crowned sparrows sang more softly in response, their songs traveled twice as far in the quieter conditions. This meant people could hear effectively four times more birds than usual, explaining why they sounded louder than before the pandemic began.
The team’s findings were published in September in the journal Science under the title “Singing in a Silent Spring: Birds respond to a half-century soundscape reversion during the COVID-19 shutdown.” Since then, news of the findings has made headlines from BBC World News to NPR Science Friday.
“COVID-19 has been devastating in many ways for our society,” Derryberry said. “The loss of human life alone is overwhelming. It’s a testament to people, though, that there are still bright spots amid such loss. One of those bright spots has been how much more people are noticing birds, particularly in cities, around the world. I hope this study seizes this moment to highlight how much noise affects wildlife and how noise is one form of pollution that people can directly address in ways that can dramatically change the quality of life for wildlife.”
Amanda Womac (865-974-2992, firstname.lastname@example.org)