Do You Hear What I Hear?

Next time you head into nature, try to tune in to the sounds you hear. It can be hard to shut out the human world, especially in the urban wild. The sounds of nature can be quite soothing. I enjoy sitting by a river and listening to the water swirl over and around the rocks, each passing H₂O molecule making those rocks a little bit smaller and contributing sediment to the sea. I also enjoy the sounds of the sea: a chorus of gulls providing backing vocals to the endless roar of the ocean.

As relaxing as sounds may be for me, they are vital to the survival of the critters. Predators, especially owls, rely on the sound of their prey to find their next meal. Prey species rely on the sound of predators to make an escape. Both predator and prey use sound (among other signals) to communicate to each other. A whistling marmot might warn others of death from above, while the howling wolf warns others to stay away from the pack’s territory. Many different animals use sound to attract a mate.

Buzzing insects, bird song, and rolling thunder are all part of the natural soundscape. Like all things in the natural world, it is vanishing. Even in national parks, noise from traffic and the devises people haul into campgrounds drown out the natural soundscape. A hike into pristine wilderness, despite its seclusion, is not impervious to intrusion from commercial airliners passing overhead.

Song sparrow getting ready for his bug number

What does this mean for the critters? It’s too soon to say. A pair of National Park Service biologists are recording the soundscapes of our national parks as a catalog and for research. The goal is to find out of our noise is diminishing our enjoyment of the parks. I am willing to bet that the average person won’t even notice the noise we take into nature, but it’s a different story for the critters.

Kurt Fristrup and Bill McQuay capturing the natural soundscape of
Great Dunes National Park in Colorado

Another group of researchers is using sound recordings to determine the effectiveness of conservation projects. These researchers, working in Papua New Guinea (north of Australia), are trying to find a cheap and easy way to tell if their work is working. In a species rich ecosystem like a jungle, getting sound recordings of the many critters coming and going may be the answer. The monitoring system is relatively inexpensive and easy enough that the semi-primitive natives can do it, giving them a role in protecting the ecosystem around them.

Setting up acoustic monitoring in Papua New Guinea

Comparison between the soundscapes of continuous and fragmented
forest cover in Papua New Guinea

Next time you head into Nature, close your eyes and take a minute to listen to your surroundings. How many natural sounds do you hear, compared to man-made ones?

This week’s stories come from NPR (National Parks sound recording) and Cool Green Nature (Papua New Guinea research).