A study documents a “conversation” with Twain the humpback whale
By KATELYN BURNS— science@theaggie.org
Whales have incredible social and vocal complexity. Similarities between human language and humpback whale songs had been noted despite humans and humpback whales being evolutionarily distant. In a study conducted in 2021 by UC Davis animal behaviorists and published in 2023 by PeerJ, a rare interaction with a humpback whale was documented.
Brenda McCowan, a professor in the UC Davis Department of Population Health & Reproduction with an interest in communication complexity in non-human animals, spoke on the whales’ feeding habits.
“These whales come to Alaska to feed,” McCowan said. “So, they’re really focused on eating, because they need to feed in order to go back to their breeding grounds where they don’t feed for six months round-trip.”
The study’s team had done a series of playbacks on other research vessels earlier in the season, with no responses. Normal protocol for playback study is to have a pre-playback period, where researchers simply record what is currently occuring, and a follow-up post-playback period, where researchers look for repercussions of the playback.
The team was using a previously recorded contact call, called the “whup call,” theorized to convey information about where they are in a space.
“There are two ways that whales can respond to a playback,” McCowan said. “One is to vocalize back [and] the other is to approach the speaker, because if it’s a contact call, like what we think the ‘whup’ is, then they might want to approach it.”
While McCowan was conducting the playback trial from below deck, other members of the team, including Josephine Hubbard, a postdoctoral researcher at UC Davis at the California National Primate Research Center who works on whale acoustics, and Jodi Frediani, an internationally recognized photographer specializing in marine species, were above deck recording behavior and identifying the whale.
“One of the gold standards for understanding what animals are saying is what they’re doing when they’re saying it,” Hubbard said.
The whale was observed to be circling the boat, coming within 100 meters. The team also noted changes in their blows, from relaxed during the initial engagement phase to wheezy during the agitation phase.
“In the same way that we have unique and individual fingerprints, whales have a unique pigmentation pattern on the underside of their tails,” Frediani said.
Using the Happywhale website, which uses Artificial Intelligence to instantly match a whale’s fluke (the underside of their tails) in a global database, the whale was identified as Twain, an approximately 38-year-old female. Twain was also identified in photos taken the previous day, during the time in which they recorded the whup call used during the playback trial. Twain was amongst eight other whales.
“She was either responding to her own contact call […] or she was responding to a contact call from one of the whales that she’d been hanging out with and feeding with the day before,” Frediani said.
While limited to a 20-minute “conversation” with just one call played back and forth, the team looks forward to longer and more dynamic playback trials in the future. For more information on the details of the research conducted and Twain, check out the team’s full study and the UC Davis website.
Written by: Katelyn Burns— science@theaggie.org