Birds sang softer, but sounded louder during COVID-19 pandemic shutdown

When businesses started closing because of the pandemic this spring, many joked that nature was reclaiming the land. It turns out that’s kind of right.

When people started staying inside over the spring, birds flew the coop.

“It’s sort of the first data showing that animals responded to changes in human behavior,” says Dr. Elizabeth Derryberry, Associate Professor of Ecology and Evolutionary Biology at the University of Tennessee, Knoxville.

She’s been studying birdsong for more than 20 years, but this year was different.

“It was so much quieter that you could hear them at a greater distance,” she says.

Derryberry and her team listened to recordings they had of white-crowned sparrows. The birds live along the West Coast, and those in the study live in San Francisco.

In recordings from 2016, they can be heard chirping. However, they’re oftentimes overpowered by the sound of nearby traffic.

In the recordings from spring 2020, the birds are singing louder, and are heard much more clearly with less background noise during the shutdown.

Derryberry says it’s all thanks to the lack of noise pollution. Without as many cars and other sources of noise pollution, the birds' songs carried farther away.

“Traffic is sort of a constant presence, this low hum, and it’s a lot of energy at low frequencies which are specifically overlapping or masking the songs,” she explains.