Learn about the science behind sound
Sound is everywhere around us. Whether we are in the woods or in a city center, all landscapes have sounds that vary throughout the day, everyday of the year. Natural landscapes are often dominated by sounds of living organisms – frogs, insects, birds, even mammals – but we also hear the quiet, background noises – flowing streams, trees swaying in the wind. In other environments, we hear the hissing of garbage trucks, sirens from emergency vehicles, and children laughing and playing in parks. Together, the sounds emanating from each environment produce a unique “soundscape”.
Sounds of Nature is a community research project to understand changes in biodiversity over time by studying these soundscapes. Globally, we are losing biodiversity – the variety of living organisms on Earth - at unprecedented rates, and the widespread decline of many wildlife species is a growing concern for society. Studying the collective biodiversity – by listening – is a promising approach to learn about the health of an ecosystem across time and space, and, with new technology, is something that all of us can do!
Citizen science – engaging and involving the general public in scientific research – is a promising approach to tackling large-scale biodiversity issues. Through Sounds of Nature, a team of researchers and the public are participating in and contributing to a state-wide project to monitor biodiversity in their backyard and beyond. Our first step in this multi-year project is to focus on one sentinel of change – birds!
Bird populations have been declining globally, with recent estimates suggesting a loss of 3 billion birds since the 1970s. Sounds of Nature’s first goal is to better understand drivers of this loss across Midwestern United States. Historically, the only way to determine where bird species were across large areas required a lot of human effort and time. For example, in Illinois, one such effort was the Illinois Breeding Bird Atlas which was conducted throughout the entire state in the 1986-91. In this project, hundreds of volunteers and organizers conducted bird counts across the entire state of Illinois. This was an incredible effort, and some really important information for wildlife conservation and management was collected, but recreating this is a monumental task. Fast forward 30 years, and we’re in a new era of wildlife monitoring, with state of the art technology available to aid in more quickly and efficiently monitoring wildlife, we can work to reduce and reverse global wildlife declines.
In Sounds of Nature, we are using innovative monitoring of soundscapes combined with the power of the public through citizen science to detect large-scale changes in biodiversity across our region. Teams of university researchers and citizen scientists use inexpensive, portal sound recorders to collect sounds for a few days across forests, grasslands, agricultural areas, and even urban areas throughout Midwestern United States. Our teams then retrieve the recorders and transfer recorded soundscapes to a computer system to be processed with modern machine learning techniques in bioacoustic analysis. Our researchers review recordings and identify birds by their calls. These representative bird calls are used to train a computer routine to automatically identify birds in hours and hours of soundscape recordings. We couple the information of which bird species are detected across with remote sensing information to understand how changes in land cover, climate, and land use have affected birds and the greater biodiversity of our region. Below is an example of an audio recording and associated spectrogram of an Eastern Whip-poor-will in southern Illinois from: