Did you know a whale could sound like horse? Or like an owl? Like a squeegee on a wet glass surface? Or like the zipper of a jacket being quickly zipped up to keep out the building winds? Or a deep rumbling purr or growl of a large cat??
For three months, I had the privilege to listen to the sounds of Southeast Alaskan humpback whales from the Five Finger Lighthouse perched on a rock surrounded by the waters of Frederick Sound. I arrived there through a collaboration with AWF Principal Investigator Dr. Fred Sharpe and AWF Research Collaborator Michelle Fournet to work on an acoustics project for my senior thesis at Pitzer College. Over the course of the summer I made over 500 hours of acoustic recordings from our autonomous hydrophone, and have logged well over 15,000 whale calls. Now I am returning to campus for my senior year, and will analyze how environmental factors, such as light and tidal activity, influence the acoustic behavior of these whales. Stay tuned!
The hydrophone I was using was autonomous—it sat out at a mooring for up to two days at a time and sent a wireless signal back to the lighthouse. From inside the lighthouse we could record and listen live -- effectively eavesdropping on the whales. It is my hope that the whales were not even aware that we were there, allowing us to gain insight into their sounds and the soundscape they live in without influencing their behavior. I got to sit and watch from my perch as a whale slapped its long flipper on the water, then hear the sound of the impact first over the hydrophone and then through the air. I got to see a feeding whale come right near the shore and blow a bubble net, hear its long and loud feeding calls, and then see its gaping mouth emerge from below the surface as it gulped the abundance of prey in these waters.
At times I would be sitting inside on my computer, scrolling through spectrograms of the previous day’s recordings and be distracted by loud 'swops' and 'whups' coming over the speaker, only to run outside and see a group of whales right nearby—presumably the same ones that had been chattering into the hydrophone. And I got to hear more than just the whales: the rain on the water, the snapping of critters on the rocks on the benthos, the movement of the water itself. And, of course, I heard the sounds made by people. Even though it is remarkably wild and untouched, boats are an integral part of the Southeast Alaskan way of life. We may hear a bit of noise from above the water, but beneath the surface these boats can be painfully loud. Whenever a boat came by I would jump to turn down the volume on the speaker. I couldn’t help but think that I was lucky to be able to adjust the volume…unfortunately, the whales don’t have that option.
I will spend the next several months listening closely to the recordings I have collected, and I am excited to dive into the data processing to see what we can learn from these sounds. I am incredibly grateful to have had the opportunity to spend my summer conducting whale research in Southeast Alaska, and as I am scrolling through spectrograms on my computer and listening through my headphones I will be picturing the waters of Frederick Sound, the backdrop of tree-covered and snow-capped mountains, and the plumes of whale breath suspended in the crisp Alaskan air. Thanks for the summer of a lifetime.