beaked whale
April 17, 2015

UPDATE: Strange whale call probably doesn’t belong to new species

Chuck Bednar for redOrbit.com - @BednarChuck

A whale call recorded by marine biologists in the frigid waters of Antarctica may belong to an entirely new species of the massive aquatic mammal, according to new research published earlier this month in the Society for Marine Mammalogy journal Marine Mammal Science.

Researchers from the University of California’s Scripps Institution of Oceanography, along with colleagues from Argentina, recorded an unusual whale signal last February – one which they were unable to perfectly match any known species of whales living in that region of the world.

Not a perfect match for any beaked whale

While sailing through Antarctic waters with four hydrophones in tow, the scientists picked up an odd signal that they identified as BW29. The signals were detected on 14 separate occasions, and according to Gizmodo, they were not an exact match for any known species of whale.

They believe that it might be a new species of beaked whale, a type of creature that experts know very little about because they spend most of their time below the surface. There are at least five known species of beaked whales living near Antarctic, the website pointed out, and this type has what is called a distinctive chirp or “frequency modulated (FM) upsweep pulse.”

Each species is said to have its own unique FM pulse, and the new song does not perfectly match any of them. The peak frequency was too high for Arnoux’s beaked whales, they said, and it did not perfectly match-up with three other beaked whale species either. The other, the strap-toothed whale, is typically found farther north, so this call may belong to an unidentified species.

The authors also recorded a second unique call, identified as Antarctic BW37, on six different occasions, according to BBC News. That signal was produced at a higher frequency, the authors reported, and it is unclear if it belongs to a different beaked whale species than BW29.

It is also possible that a single species may produce multiple signal types, although this had not yet been demonstrated in any species of beaked whale, the British media outlet added. Given that a new species known as Deraniyagala‘s beaked whale was only confirmed last year (bringing the total known to 22), there is a good chance that there are still species to be discovered.

Researchers downplaying possibility of new species

Interestingly enough, when we got in touch with Dr. Simone Baumann-Pickering, an assistant research biologist at the Scripps Whale Acoustics Lab, she told us that it was “unfortunate that the press has picked up on the notion that we’re dealing with a new species of beaked whale.”

“While that is a distant possibility that we needed to mention in our manuscript to cover all grounds it is not the most likely answer,” she explained to redOrbit via email. “I believe, e.g. that the BW29 signal is produced by Southern bottlenose whale – but we can’t say that because we don’t have absolute evidence. I’m also basing this statement on further data we gathered on a 5 month-long bottom-moored recording where this signal occurred quite frequently in a location where regular occurrence of southern bottlenose whales have been documented.”

Rather, she wanted to emphasize that the main accomplishment of the research (which was part of an ongoing collaboration with Argentine researchers conducted underneath the umbrella of the Southern Ocean Research Partnership) was “the great possibilities of passive acoustic monitoring of species that are otherwise extraordinarily difficult to encounter, particularly in an environment as remote and largely inaccessible for most of the year like the Antarctic.”

Thanks to unpublished data gathered as part of this ongoing research project, Dr. Baumann-Pickering explained that she and her colleagues “now have a first impression” of the seasonal behavior of these whales, and could eventually come away with “an improved density estimate with enough spatial and temporal coverage.”

“Certainly, we will be able with these kinds of recordings to observe changes over time in the future that may occur in relation to changes in the environment, such as possible changes in prey abundance due to increased water temperatures and decreased ice coverage,” she concluded. “It’ll give us an insight into the behavior and the ecology of these animals.”

Editor's note: We'd originally written this like the rest of the media--that there was a good chance it was a new species. We ran the story before getting the quotes from Dr. Baumann-Pickering, and we were very glad she corrected us. We also originally referred to the sounds as a "song". But Dr. Baumann-Pickering corrected us again, saying that "songs" only belonged to baleen whales.

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