Page 44 - Spring 2018

Hans Slabbekoorn
Postal:
Institute of Biology Leiden University Sylviusweg 72 2333BE Leiden The Netherlands
Email:
h.w.slabbekoorn@biology.leidenuniv.nl
Soundscape Ecology of the Anthropocene
Noisy human activities change natural soundscapes. This not only affects the health of people but also acoustic communication in animals.
Living the Anthropocene
“A picture is worth more than a thousand words and a soundscape is worth more than a thousand pictures” (Krause, 2013), but can we still enjoy those pictures today? It is a moment of joy for many to hear the first birds starting the dawn chorus in the dim light on a calm day in spring. It is the serenity of a quiet landscape gradually emerging from darkness and morning haze, against which the first bubbling notes and warbling melodies stand out so beautifully. However, today, many people who go outside early enough will likely hear something else: cars and trucks from near- by highways, noisy generators or air conditioners, street cleaners out sweeping the streets, construction sites gearing up for the day, or trains and planes transporting people to their destinations.
The Anthropocene is the current geological era, where natural habitats are increas- ingly affected and modified by the presence of human activities such as those that produce sound (McKinney, 2002; Slabbekoorn and Ripmeester, 2008). Indeed, many human activities are noisy and often cause a prominent acoustic modifica- tion of habitat, which may affect humans and animals alike (Barber et al., 2010; Brooks et al., 2014). Natural soundscapes without an acoustic trace of human pres- ence have become increasingly difficult to find (Mennitt et al., 2015). Does it mat- ter that people now only rarely experience moments of relative quiet? Does it mat- ter to the birds that their environment has become noisier, often when they are at their daily peak of singing activity? Well, yes it does.
We know that people can get ill as a result of noisy conditions (Passchier-Vermeer and Passchier, 2000). The plethora of industrial and urban sounds or just one spe- cific buzz or hum can annoy people and cause heart problems, sleeping distur- bance, and all sorts of stress symptoms and hearing deficits. Moreover, human per- formance in precise tasks that require focus declines with rising levels of ambient sound. It has also been shown that cognitive development is impaired for children in schools near noisy airports.
How noisy conditions affect animals may be more difficult to grasp. However, birds are well studied and provide insights into how noise may impact their behavior and communication (Francis and Barber, 2013; Wiley, 2015), and how it may affect stress physiology, survival, and reproduction (Halfwerk and Slabbekoorn, 2014). All of this may translate into impacts on avian populations, communities, and ecosystems (Francis et al., 2009) and and may provide critical understanding about how in- creased noise levels in the environment affect other species, from fishes to humans.
In this article, I focus on the scientific discipline of soundscape ecology (Slab- bekoorn, 2004; Pijanowski et al., 2011) and the role of sound in the natural world of animals. I provide particular examples of insight gained from studies on birds. A picture of remarkable and informative acoustic diversity, shaped by natural se-
42 | Acoustics Today | Spring 2018 | volume 14, issue 1 ©2018 Acoustical Society of America. All rights reserved.