The Language of Their Ancestors.
Humpback whales are known for their songs. Male humpbacks sing, sometimes in unison, during the mating season when they are in warm, equatorial waters. These haunting, repetitive vocal displays change and evolve into entirely new tunes all the time, including over the course of a single season. But researchers are now discovering that unlike their mating songs, the whale's speaking language --that is their repertoire of calls, which include growls, trumpets, and ahoogas --remains the same over long periods of time. In fact, a new study shows that some whale calls are passed down across multiple generations.
In a new analysis of four decades of recordings of whale calls in Southeast Alaska--where the marine mammals migrate in summer to forage --researchers found that, of the 16 humpback whale call types recorded, eight call types were present in all four decades of recordings stretching from the 1970s to the 2010s. The researchers, whose study was published in September in Scientific Reports, the journal Nature's online supplement, found that some calls were repeated across as many as three generations.
The discovery is reshaping what scientists know about how and why whales talk to each other.
"We are just now beginning to understand 'the other side' of humpback whale communication, and it is very different from what males sing on breeding grounds," Michelle Fournet, an acoustic ecologist who led the study at Oregon State University in Corvallis, told Discover magazine. "What we can begin to investigate now is why these calls persist," says Fournet, who is now a researcher with the Cornell Bioacoustics Research Program in Ithaca, New York.
Since multiple populations of whales use the same types of calls, Fournet suspects some of the vocalizations may be how individuals identify themselves. Other kinds of calls, such as those linked to hunting Pacific herring, may be unique to humpbacks in the North Pacific. "Documenting longevity of calls within Alaskan humpbacks allows us to truly begin asking questions about what these calls mean, and why whales produce them," she says.
Caption: New research indicates that humpback whale calls can be passed down generations, a discovery that is reshaping what scientists know about how and why these whales talk to each other.
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|Title Annotation:||CALL OF THE WILD; humpback whales calls|
|Publication:||Earth Island Journal|
|Date:||Jan 1, 2019|
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