Since mid-March, when pandemic measures took effect around the world, a research team has been listening intently to bird calls on and around the San Francisco coast.
It made a surprising discovery: the birds sang quieter than previous years. And not only that. Their behaviour has also changed.
They listened to the white-crowned sparrow from the sparrow family. In the countryside, where only the wind and sea waves can be heard, they sing differently than in a loud city.
Vehicles produce constant noise at low pitcj. We hear it everywhere in the city. Due to this city noise, songbirds also hear each other less well.
»Not being heard can cause problems for the bird because they use their song to attract a mate and to defend their food and nest. A number of songbirds have adaptations to limit how much the noise covers up their songs,« research team leader Elizabeth Derryberry told Časoris.
In order for the birds to drown out the noise from the surroundings, they began to sing louder and at a higher pitch in the city. At a time when public life was calming down due to the novel coronavirus pandemic, however, city noise was greatly reduced and this also affected bird singing.
»In fact, it was so much more quiet it sounded more like the city was when your grandparents were young. When the noise levels went down, birds in the city changed their song – they sang more quietly, at a lower pitch and a wider pitch range,« added Elizabeth Derryberry.
Their song became more like the songs of birds in the countryside. Their singing was heard twice as far as usual.
Their behaviour has also changed. Males have become less agressive.
Points to Consider
- What good came out of the pandemic?
- Do you speak louder in a loud environment?
- Which migratory birds do you know?
The original version of this article was published on November 2nd.
English translation courtesy of JL Flanner, Total Slovenia News, an English language website with news from and about Slovenia.