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Sperling: During the lockdown, San Francisco was as quiet as it was in 1954
Photo:
Francois Gohier / Ardea / imago images
While public life in San Francisco largely came to a standstill for months due to the corona pandemic, sparrows have developed unimagined singing skills in the sudden calm.
The male specimens of the badgers belonging to the sparrows suddenly chirped more gently, improved the range of their voices and thus became more seductive for the females, report researchers in the journal "Science".
"When the town was noisy, the birds sang really loud," said lead author Elizabeth Derryberry of Tennessee University.
When extensive exit restrictions were enacted in California in the spring and traffic slowed significantly, the noise in San Francisco fell by half and fell to the level of 1954.
Like people at a party
The researchers compared recordings of roof shouts from last year with recordings taken at the same locations in April and May 2020 and found that the birds now chirped significantly more quietly and hit lower tones.
Derryberry compared the bird calls with human behavior at parties: While you can still talk normally at the beginning of the evening, you have to speak louder and louder the more guests come.
"If you shout at a cocktail reception, the voice is not exactly the best," said the researcher.
It is the same when the sparrows have to yell against the noise of the city.
With the decrease in noise during the Corona restrictions, the males would suddenly have sounded much "better and sexy": "To females, they sounded like better partners."
Although the males now called more quietly, they could be heard in the quiet city in a radius twice as large as before.
According to the researchers, the findings of the study show how quickly birds can adapt to changing conditions.
Long-term solutions to reduce noise could have positive effects such as greater biodiversity.
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koe / AFP
