North America and Europe are becoming quieter -- as far as birdsong is concerned, according to a new paper.
A declining trend in bird communities is making the developed world a quieter and less varied place in regards to birdsong, according to new research. While this might not sound like a pressing concern on the face of it, the findings do point to greater ecological issues brewing in the background. Songbirds perform important services in natural environments and their decline could impact the health of our immediate surroundings.
At the same time, for those living in densely urbanized environments, birdsong can be a very powerful element helping us maintain a connection to nature. Its loss could thus have important implications for public health and our overall well-being.
"The results suggest that one of the fundamental pathways through which humans engage with nature is in chronic decline, with potentially widespread implications for human health and well-being," reads the study's abstract.
For the study, the authors collected bird counts via annual survey data and recordings of birdsong taken over the past 25 years at various sites across North America and Europe. Data from citizen science monitoring programs across more than 200,000 sites in 22 cities in Europe, the USA, and Canada was also used.
Starting from this dataset, the team matched all recorded vocalizations to the relevant bird species in order to better understand exactly which birds inhabit which cities across the investigated area. The recordings were also used to produce a 'composite soundscape' for each year at each site.
All in all, this showed that the total amount of birdsong and its diversity have been steadily declining across all sites. In other words, the soundscapes most of us in the USA, Europe, or Canada experience have been getting quieter and less varied over time. This suggests that bird species are experiencing an ongoing decline both in numbers and variation across the investigated area.
The first conclusion to be drawn from these results is that, if we want to prevent further deterioration of the soundscapes we're exposed to, we need to start conservation efforts for the birds that inhabit our cities and beyond. According to the authors, that's definitely something we should want to do: natural soundscapes are one of the few remaining ways that city inhabitants get to connect with nature. Such experiences have a direct and beneficial effect on our well-being. The loss of soundscapes or degradation of their richness can thus have a negative effect on the well-being and quality of life for whole communities at the same time.
With half of the world now living in cities, it would be in our best interest to heed warnings like those offered by this study.
The paper "Bird population declines and species turnover are changing the acoustic properties of spring soundscapes" has been published in the journal Nature.