From the Guardian –
New research shows that male birds trying to compete with traffic and city sounds are singing louder and at increasingly higher frequencies, which could harm their vocal cords and hearing. As a result their songs are becoming more chaotic and less diverse, which makes them less attractive to female birds and damages their mating opportunities. Some birds, including robins, are choosing to sing at night instead of during the day. This not only makes them more vulnerable to attack but, because the birds need to be awake in daylight hours to feed, creates stress and exhaustion.
‘The difference between urban and rural birdsong is becoming so great that the two groups could now be unable to communicate, leading to inbreeding and a weakened gene pool,’ said Dr Sue Anne Zollinger, of the University of St Andrews, who has studied the impact of environmental noise on birds’ song learning and development. A group sharing a small gene pool, said Zollinger, was less likely to be able to adapt quickly to new diseases or environmental pressures, putting them at risk of being wiped out.
Mark Constantine, author of The Sound Approach to Birding and founder of the Sound Approach database, the fourth-largest natural sound archive in the world, said: ‘Birdsong is used as an indicator of quality of life and has been proved to reduce our blood pressure. When we live in the centre of large, urban areas, we get more stressed and it’s extremely good to have birdsong around us. The impact on humans of birdsong is massive. It harms us, as well as the birds, if their songs become simpler, shriller and louder.’
Having recently moved to a rural village from London, it’s not only the birdsong that’s different (it’s more varied, given the greater variety of birds – which is nourishing). The pace of life is noticeably different, of course. But it’s also, I’m sure, people’s capacity to perceive the variety in their surroundings; how much of urban life is given over to an ever-narrowing focus on human fashions, technologies, and discourses, marginalising the ‘more-than-human’ world? And marginalisation of the more-than-human world tends to equate with a high environmental impact: as Lucy Siegle pointed out in a parallel article, urban noise is highly correlated with our so-called ‘carbon intensity’.