Whales and researchers "whup" it up around Five Finger
a piece for my local paper the Petersburg Pilot
The Sound Science Research Collective returned to Five Finger Lighthouse again in the summer of 2022. And earlier this month they shared some results from their 2019 field season in an online presentation for the Five Finger Lighthouse Society by Dr. Leanna Matthews, detailing their playback study with humpback whales.
"Usually when people think about whale song, they think about humpback song, but song is not the only thing they do. Song is produced on the breeding grounds, on those lower latitude breeding grounds, like in Hawaii," said Dr. Matthews. "It's only sung by males, in what scientists presume to be a breeding context. And it's learned; it changes every year, and it's learned by these individuals. But humpbacks don't come to Alaska to breed, so they don't really sing when they're in Alaska. They come to Alaska to eat, and while they're in Alaska on their foraging grounds, they produce lots and lots of different types of vocalizations."
These "non-song vocalizations" are referred to as "calls," and unlike song produced by males during breeding, calls appear to be produced by all ages and sexes of humpbacks.
Despite their widespread occurrence, humpback calls weren't studied until the late 2000s; the first call catalog of Southeast Alaskan humpbacks was done by Sound Science's director, Dr. Michelle Fournet in 2014.
The cataloged humpback call central to 2019's experiment was the "whup."
A whup is a type of low groan that lasts about a second, similar to the noise a big calm dinosaur might make in "Jurassic Park."
"Do humpbacks use this call to make contact with other humpbacks? To answer our hypotheses, we would need to engage in a conversation with the whales," said Dr. Matthews.
The scientists chose the area around Five Finger Lighthouse because there is a history of science in the area recording the social structure of local whales. There are usually whales there, and it is usually quiet enough to both hear whales and have whales hear researchers.
Each day, the researchers had to find whales. Then, to determine if they had surveyed the same whale before, they photographed the whale tails, or flukes, and uploaded the images to happywhale.com, which, much like a human fingerprint database, helped identify individual whales.
Next, the researchers would deploy four hydrophones: each unit weighted down to 100 ft below the surface with buoys and GPS units and positioned about a thousand meters apart, roughly in a box shape around the whale.
"If all four of those hydrophones record a sound that's happening underwater, we can use the locations of those hydrophones and the times at which those underwater acoustic signals arrive at our hydrophones to localize that sound," said Dr. Matthews.
"... We put ourselves . . . back into the middle of our box so we could do our playback experiment. And hopefully-fingers crossed-if we built our box correctly, our whale was somewhere in the middle of that box...after all of that, it was finally time to do our playback experiments."
"We count the whales and we document their locations for ten minutes before we do anything, then we put our underwater speaker into the water and we do the same thing, we count the whales and we document their locations for ten minutes while sounds are being played, then we do it again for ten minutes after the sounds are over."
The researchers hypothesized that the whup sounds function among the whales as a form of making contact.
To test the idea the researchers also played a "control signal" into the water.
"We want to make sure that if we are seeing a response to these whup calls, that it is related to these whup calls, and not just related to the fact that we're playing a sound from a speaker," explained Matthews. "We had one type of control that was just underwater noise, and we had another type of control that was different tones, in the hearing range of humpbacks. Something that's the same length as a whup, something that's the same pitch as a whup, but something that is not biologically meaningful, and shouldn't change their behavior."
The experiment was also a blind experiment, meaning that the observers didn't know if they were playing a whup or a control noise.
"...We found that whales respond when we talk to them . . . In all of our trials, 100%, there was an increase in call rate when we were playing whups to the humpback whales," confirmed Matthews. And for their control signals, the opposite was true. "There's no significant difference happening here with our calling rate when we're playing something that's just water noise or just tones."
The research team is excited, "What these whales are doing feels very familiar. One whale is speaking and another whale is responding. These whales have a culture, and we're starting to tap into that," said Dr. Matthews. "We also believe that this work makes us good listeners, which is a really important skill to have...to exist in silence and to hear the world around you is important."
During the Q&A portion of the presentation, the lighthouse keepers who hosted the scientists at Five Finger, Pat and John Gans, wondered if above-water sounds could be important, since it's something they often hear at the lighthouse.
Dr. Matthews said that above-water sounds haven't been studied much yet, but she believes they may be more motivational and referred to recordings made in Glacier Bay in 2015 and 2016, saying, "If they're aggravated, the sounds sound aggravated, and that's a very human emotion to put on them, but if you've heard a lot of these sounds you can kind of hear when they're upset about something."
When asked if she feels we're making progress towards understanding whale communication, Dr. Matthews responded, "I don't know if I'm comfortable saying we'll ever fully understand it. It's a really difficult thing to take your humanness out of it. As much as these animals are complex and intelligent, they're not humans, so the way that we're interpreting what they're doing sometimes can have a human influence, and it's so different that I don't know if we'll ever fully understand it."
Read more news from my hometown at www.petersburgpilot.com