Urban Zoology - The Nightingale Screams
Zafarir Rinat, Haaretz, voila!
nightingale. Their volume in noisy areas is similar to the noise emanating from the exhaust of a motorcycle that is operating at full power
https://www.hayadan.org.il/zamir090504.html
The song of the nightingale served as an inspiration to poets and composers, and was even immortalized in the song sung by Frank Sinatra "The Nightingale Sings in Berkeley Square". But in Berlin, the nightingales - through no fault of their own - became an acoustic hazard. According to a new study, the male nightingales had to adapt to the strong background noise of the urban environment, and significantly increased the volume of the sounds they produce so that they could continue to communicate with their own kind.
The research, which aroused great interest and was featured on the front page of the London "Times" this week, was carried out by Henrik Bram from the Free University of Berlin, and was published in the latest issue of the scientific journal "Ecology Journal Of Animal". Bram decided to compare the loudness of male nightingales in noisy areas of Berlin, where main roads and trains pass, with the loudness of male nightingales in quieter areas (for example, forests and groves).
One of the areas Bram checked is Potsdam in the heart of Berlin. In this area, it was found that the nightingales had to make sounds with a power of 93 decibels, so that their voices could be heard over the noise of the cars. This intensity is similar to the noise emanating from the exhaust pipe of a motorcycle operating at full power. According to him, the finding of the higher volume of males in noisy areas is the first case that documented an adaptation of the volume of an animal's voice to changes in its living environment.
"A nightingale singing in your ear can damage your hearing," Baum said in an interview with The Times. "In Germany, you must protect your ears if you are exposed to a noise source of 85 decibels or more for a period of one hour or more. Therefore, if you pass by a nightingale - you should have ear protection."
The loudest nightingale song in central Berlin was 14 decibels louder than nightingales in quieter areas. Bram says the nightingales have to put more strain on their lungs but he found no evidence that the loud singing harmed the nightingales' health or made them hoarse. However, he points out that songbirds are adapted to sing like an opera singer, so it is likely that they tire more quickly when they exert themselves - and their ability to sing is impaired.
Singing is essential for males especially in the months of April and May, when they return from Africa - where they spent the winter - and are looking for a female to start a family. Nightingales apparently use several hundred songs. "Increasing the voice allows them to communicate over a measured distance to defend territories or to attract females," Bram noted in the article, "however, because the quality of the singing varies, this may have broader effects on their behavior."
According to the guide to the birds of Europe and Israel published by the Society for the Protection of Nature, the United Kibbutz and Mapa, the nightingale, when in danger, emits a high-pitched hiss that sounds like a "yoop" and a stiff rattle that sounds like an "arrrr". "The singing is powerful, varied and melodic," the guide points out, "it consists of fairly short segments of two to four seconds, with pauses of a similar length in between. The singing includes curling sections, flute sound sections and a variety of other sounds. But it is especially evident in the section of whistling that repeats itself in a crescendo along the lines of 'lo lo lo lo li li'".
They know evolution in action
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