New study: Bird songs and sounds disappear from nature
Because we hear birds more than they see them, their chirps represent one of man’s rare connections with nature.
A research team working on the evolution of the ‘vocal scene’ in Europe and North America has observed a significant decline in the range of sounds produced by different bird species.
And writer Fahi Ter Minassian says – in a report published by the newspaper “Le Monde” (the world) French – When a city-dweller wants to reconnect with nature, the first thing he does is wander through the gardens, countryside and forests where he enjoys hearing the different sounds of creatures, especially birds. But this element seems to be disappearing from nature.
In a study published in magazine Nature Communications on 2 November.
Simon Butler, from the University of East Anglia in the United Kingdom, and his colleagues explained how they combined bird-watching data with vocal recordings to simulate the vital activity of birds over a quarter of a century at 200,000 sites on both continents. Unfortunately, their findings were troubling; The “symphony” of spring turns out to be getting poorer over time.
Half a century ago, it launched bird-watching campaigns that mobilize volunteers who, during the spring, count bird sites in areas of 4 square kilometres. In France, the chronological monitoring program of common birds of the National Museum of Natural History during 32 years managed to monitor about 2,900 sites where birds live.
According to the curator of the National Museum of Natural History Benoit Fontaine, “This long-term work has made it possible to highlight the severe decline in bird numbers, especially in agricultural environments where specialized species such as the ghetto lark are gradually disappearing, and are replaced by other common types of birds, such as the wrachon. familiar (similar to pigeons and slightly larger than them) or titmouse (a family of sparrows).”
Environmental acoustics..a new specialty
How do these changes affect the sound landscape of cities and countryside? Because we hear birds more than we see them, their chirping represents one of humans’ rare connections with nature.
To answer this question, Simon Butler and his colleagues recorded 25 seconds of each bird’s sound of a specific species. Then, they mixed these sounds in order to create synthetic 5-minute audio clips at each location and for each era according to the time of observation. Then they analyzed these audio files using “environmental acoustics” tools.
Created in 2014 in response to requests from the National Museum of Natural History and the University of Urbino (Italy), this modern discipline studies natural sound with the aim of answering questions of an ecological nature such as how bird species evolved in different habitats. The team developed techniques to analyze thousands of hours of bird vocal recordings collected at their experimental sites.
“One of the processes we do is compress audio files into 1-minute packages to extract up to about 50 distinct audio cues to determine the acoustic richness of a site,” explains Sylvain Hubert, research engineer at the French National Center for Scientific Research at the National Museum of Natural History.
Simon Butler’s group has proven that the sound scene has deteriorated in complexity and variety. This study is unique, as Sylvain Hubert believes that “the decline in the number of birds is reflected in the decline in the sounds they produce in nature.”