Yesterday we happened to listen to Ira Flatow’s Earth Day broadcast about the emerging science of Soundscape Ecology. (Click on the image to listen for yourself, and know more on Saturday than you knew on Friday.) This field uses recordings of the blend of audio from both living and nonliving agents to analyze the overall health of the landscape. You shouldn’t be at all surprised to learn that rich, complex habitats that support biodiversity contain a biodiversity of sounds as well. On the other hand, very exploited regions that sustain few species contain little diversity of sound.
So far so good. It got me thinking of the soundscape of our beaver pond and the diversity of life it supports. What sounds contribute to the overall chorus? The most obvious sound being the tail slap, the rattle of the kingfisher, the croak of frogs. The snort of otter and the splash of fish leaping comes to mind. But other less obvious sounds would come into the picture as well, the chirp of barn swallows, the scrape of pond turtles, the faint chewing of muskrat, the whisper of wings as cormeronts take off and the skidding of feet as ducks land. In the summer you might hear the mumbled greeting of kits as they ask adults for attention or enjoy their bit of branch so much they implore others not to share.
That’s half the beaver world. What about the other half? What about UNDER the water? Is the hydroponic soundscape of a beaver pond different than the same recording of standing water? You bet it is, and who is doing that research? What does a tail slap even sound like under water? How far does the sound travel and can beavers hear the warning even when they’re diving?
- Click to hear a tail slap
- what it sounds like underwater
Here’s a question I never thought of before and have never read anything about. Do beavers vocalize underwater? Can they make their little whining call back and forth to each other? Can kits call their parents for a ride underwater? Can adults warn kits to stay low when danger is near? If beavers do communicate underwater what does it sound like? How far does it travel?
So once again, I wrote every beaver expert I could think of about the question, and the answers are still trickling in. Mostly they read as “I have no idea! Who has ever thought about that question?” And of course the answer is, um…yours truly. I got a heart-breaking story from a friend of a friend who does acoustic ecology recordings and had never heard of beaver vocalizations being recorded underwater, but thought it was likely and was interested. He told of an adult malee recording his friend got when a dam was blown up killing the mate. That night the male swam about the ruined pond crying in what he says was the saddest sound he’d ever heard from human or animal.
Sigh.
We need beaver recordings underwater, and more information about the tools they use to communicate out of sight. I will end this conversation with the most vibrant, mournful and wild sound I have ever heard. Wait until the sun sets.
- Soundscape Algonquin National Park Canada
