As San Francisco went into lockdown and locals found new projects to pass the time, so too did birds in the area.
New research shows that the white-crowned sparrow, a bird that lives in both urban and rural areas, responded to the sudden peace and quiet by learning a new song. Now that it doesn’t have to 'shout' over the metropolitan cacophany, it can focus on the complexity of its call - a fascinating illustration of how lockdown has changed the world around us.
To adapt to the San Francisco area, city sparrows sacrificed the quality of their song so that they could get loud enough to be heard over the din. But with less noise around due to lockdown, the sparrows gradually adopted the more intricate - and appealing to mates - song of their rural counterparts, according to research published last week in the journal Science.
“The pandemic has been terrible in a lot of ways,” University of Tennessee behavioral ecologist and lead author Elizabeth Derryberry said. “But as a scientist, there’s this exciting opportunity for a natural experiment there: We remove noise from a whole soundscape and see what happens.”
The research comes from an unprecedented opportunity to study animal adaptation. Scientists have introduced birds to louder volumes, but couldn’t take them lower than an existing baseline. So when the sparrows actually got quieter than expected, it challenged a lot of ornithologists’ assumptions.
“Even though they sing more softly, you can hear birds at a greater distance now,” says Derryberry.