Dark finale: Birdsong dies out in Europe and North America
The catastrophic effect of climate change is reducing the volume and variety of birdsong in Europe and North America, new research reveals.
An international team of researchers led by the University of East Anglia (UEA) has developed a new technique, combining cutting-edge citizen science bird monitoring data with records of individual species in the wild, to reconstruct the soundscapes of over 200,000 sites over the past 25 years.
The team unveiled a “widespread decline in the acoustic diversity and intensity of natural soundscapes.”
Lead author Dr Simon Butler of the UEA School of Biological Sciences explained: âWe have seen a widespread decline in the acoustic diversity and intensity of natural soundscapes, driven by changes in the composition of bird communities.
“These results suggest that the soundtrack of spring is becoming calmer and less varied, and that one of the fundamental pathways through which humans engage with nature is in chronic decline, with potentially far-reaching implications for health and life. human well-being.
“Since people primarily hear, rather than see, birds, reductions in the quality of natural soundscapes are probably the mechanism by which the impact of ongoing population declines is most keenly felt by the general public. “, he added.
Dr Butler added, âThe benefits of contact with nature are widespread, from improved physical health and psychological well-being to an increased likelihood of participating in pro-environmental behavior.
âBird song plays an important role in defining the quality of nature experiences, but widespread declines in bird populations and changes in species distributions in response to climate change mean that the acoustic properties of landscapes natural sounds are subject to change. “
Annual bird count data from the North American Breeding Bird Survey and Pan-European Common Bird Monitoring Scheme sites were combined with records from over 1,000 Xeno-canto species, an online song database and bird calls, to reconstruct historic soundscapes.
The acoustic characteristics of these soundscapes were then quantified using four indices designed to measure the distribution of acoustic energy across frequencies and time. These cues are determined by the complexity and variety of songs among the participating species, but quantify the diversity and intensity of each soundscape as a whole.
The researchers say the relationship between changes in the structure of bird communities and the characteristics of the resulting soundscape is not easy to predict.
Dr Catriona Morrison, post-doctoral researcher at the UEA School of Biological Sciences, conducted the analyzes. She said: âSadly, we are living in a global environmental crisis and we now know that the diminishing connection between humans and nature can contribute to it.
âAs we collectively become less aware of our natural surroundings, we also begin to notice or care less about their deterioration. Studies like ours aim to raise awareness of these losses in tangible and identifiable ways and to demonstrate their potential impact on human well-being. “