The Pandemic Shutdown in San Francisco Had Sparrows Singing Sexier Tunes | Science


Elizabeth Derryberry has been studying the songs of white-crowned sparrows for over a decade. Her 2012 work recording and analyzing birdsongs helped demonstrate that San Francisco sparrows slowly shifted their songs to a higher register to be heard above the hustle-and-bustle of city life. In March of this year, when shutdown measures in response to the COVID-19 pandemic rendered the city’s once-busy streets nearly silent, Derryberry was struck with an idea.

“It wasn’t until I was looking at some photos of actually the Golden Gate Bridge, I was like, ‘Oh my goodness. There really is a lot less traffic,’” says Derryberry. She wondered if the city’s sparrows—the same ones adapted to sing through the drone of city sounds—were shifting their songs. Derryberry hypothesized that without the onslaught of low-frequency sounds characteristic of urban life, the sparrows would drop their volume and pitch. In new study published this week in Science, she demonstrated just that.

“It’s like a cocktail party,” says Derryberry. “When it gets louder and louder in the room, you get louder and louder. Then when the party ends, you don’t keep shouting all night.”

To find out if and how the sparrows’ songs had changed, Derryberry and her colleagues looked at two sets of recordings: the first, from the spring of 2015; the second, from the spring of this year after shelter-at-home mandates. The recordings were taken in the same places, included locations in urban San Francisco and surrounding rural areas of Marin county.

When Derryberry’s team compared the recordings, they discovered that in spring 2020 city sparrows made a dramatic shift to lower, quieter song, while in 2015 the songs stayed high and loud. Rural birds in 2020 sang lower songs too, though their changes weren’t as dramatic as those of the city sparrows. As a