Birds in Moscow began to sing at higher frequencies so that their voices would not be drowned out by low-frequency traffic noise. The differences between urban and suburban birds are confirmed by measurements, although they are almost imperceptible to the ear. Artificial lighting also changes the birds' schedule: in winter, the blue tit can start singing long before dawn - AGN.

Birds in Moscow began to sing at higher frequencies so that their voices would not be drowned out by low-frequency traffic noise. The differences between urban and suburban birds are confirmed by measurements, although they are almost imperceptible to the ear. Artificial lighting also changes the birds' schedule: in winter, the blue tit can start singing long before dawn - AGN.