When San Francisco residents began sheltering in place during the pandemic, everything got quieter, including the songs of birds.
“When they’re not busy screaming at the top of their lungs, they can actually sing more complicated songs, or what we call higher performance songs. So they’re singing a wider range of notes, and they’re changing the way they sing their trills, the rate,” says Jennifer Phillips, a postdoctoral fellow at Cal Poly San Luis Obispo who studied how the pandemic affected bird songs.
She adds, “Some of my earlier work showed that these wider range of notes are sexier, basically. So it should be better at attracting a mate and defending a territory. So for this species at least, it’s the male that mostly sings, although females can sing as well.”
Would less city noise lure back quieter birds? Phillips says this is where researchers can start thinking about conservation solutions for birds that used to be in the city, such as the California Quail.
But when people start commuting again more, or are just out of their homes more, would these sparrows change their voices/songs back? “Amplitude will adjust accordingly. They’ve shown that flexibility. It’s the performance with that I’m not sure about. That’s what our future studies will hopefully find some answers to,” she says.