There are fewer and fewer birds in the spring

The beautiful singing nightingale could be heard less and less.Photo by Sylvain Corder / hemis.fr

Because acoustic recordings were not made systematically in fixed locations during the 25 years, researchers have developed a method of reconstructing “healthy landscapes” from the last 25 years. They used “civic science” sources, such as counting data and audio recordings of individual birds (of about a thousand species) from these regions. These recordings came from zeno singing A global database where anyone can publish recorded bird sounds. For example, researchers reconstruct healthy landscapes for about 200,000 sites each year, adapting each species to the proportion of counting data in intact landscapes. Thus, they noticed a declining trend in the phonemic complexity of the “soundtracks”. In other words: in most areas it has become calmer and less diverse. Fewer birds chirping, fewer species.

Researchers publish their findings Tuesday in the scientific journal Natural compounds. In this they refer, among other things quiet spring, Title book The American biologist Rachel Carson outlined the potential consequences of pesticide use on nature in 1962. This scenario seems to have become a reality with this research.

It is known that biodiversity – also among birds – is declining around the world. If there are fewer types and numbers, then it is natural that there are also fewer that can be heard. However, the connection is not direct, the researchers wrote: “The loss of species such as the lark or the nightingale, with rich and complex songs, will probably have a greater impact on the soundscape than the loss of coriander or gull species, but will also depend on the number of other types. present.

During the reconstruction of the intact landscape, the researchers only looked at birds. The birds of each species have not been studied, and no inventory has been made of how the sound landscape has changed in each country or place. Other animal species have not been “measured”, but researchers estimate that as biodiversity has declined, the presence of their noise has also changed and declined. External factors, such as noise from air movements, cars and other human activities, were also not incorporated in the reconstructions.

According to scientists, the importance of research lies, among other things, in human well-being and appreciation of nature. According to scientific studies, the “experience” of nature contributes to this well-being. Bird sounds are an important factor in this because many people hear birds before and more often than they see them.

Hans Slapikorn, associate professor of auditory ecology and behavior at the University of Leiden, who was not involved in the research, describes it as “a fun and valid way to get birds to listen for years.” Whether the reconstructions are accurate in the absolute sense is less important to him: “If you always use the same method, you still get an accurate representation of trends. You can see a clear downward trend in the patterns that have emerged over the years, with less variation and a more uniform soundscape of the birdsong.

Slapikorn also mentions the differences between North America and Europe as striking: “Development in Europe seems to have gone faster than in America. I can not judge that. Probably because there are many urban landscapes in areas with poor results. ” Time and time again, research has shown that traffic noise and light pollution have a significant impact on the number of birds.

A remarkably versatile singer in the bird kingdom: The Nightingale.  Statue of Corder Sylvain / hemis.fr

A remarkably versatile singer in the bird kingdom: The Nightingale.Photo by CORDIER Sylvain / hemis.fr

Leave a Comment