Interestingly, these playback studies often resulted in males approaching the source of the played song, sending researchers back to the drawing board. Why would a male humpback whale approach another male on the breeding grounds? A popular theory surrounding this idea is that the males might use songs to coordinate their behavior. While singing, a male humpback is advertising his position whether he wants to or not.
This could invite competition from other males, or those other males might be looking for partners in an alliance. In another new paper, researchers at the University of Brest in France found that the pitch of Antarctic blue whale, pygmy blue whale and fin whale vocalisations fell from to at various recording sites in the southern Indian Ocean. Essentially, the whales have gotten slightly quieter, says Emmanuelle Leroy, now a research fellow at the University of New South Wales and an author of the new research.
Her team has two hypotheses to explain the drop in pitch across years. Or perhaps with oceans acidifying because of climate change , the calls are naturally carrying farther, allowing the whales to reduce their volume. The team does not believe the change in pitch is tied directly to human activity. Their research, published in the Journal of Geophysical Research: Oceans , also showed that the call pitch of the Antarctic blue whales varies across seasons, with pitches increasing 0.
These extremely loud sounds — like the cracking of ice in a glass — make it harder for the whales to hear one another, so they crank up the volume, Leroy says. Noad thinks the overall drop in pitch could be a reflection of the ageing of the population, with older whales making deeper sounds. Contrary to other scientists, he also believes that whales can hear human-made noises from quite a distance, in the same way that people in urban environments can hear the distant rumble of traffic even if there are no cars passing directly by.
But for unknown reasons, blue and fin whales are still struggling; just a few thousand Antarctic blue whales remain. In yet another new study related to whale song, researchers at Woods Hole found that short-finned pilot whales living off the coast of Hawaii have their own vocal dialects, suggesting that different groups are purposely avoiding one another.
The new studies provide a better sense of the social ties between whale groups, which could promote understanding of their genetic diversity and evolution , as well as conservation, the researchers say. Join thought-provoking conversations, follow other Independent readers and see their replies.
Whistles and pulsed calls are used during social activities. Pulsed calls are more frequent and sound like squeaks, screams, and squawks to the human ear. This is most likely so that whales can differentiate between whales within their pods and strangers. Male humpbacks can be seen singing either alone or in a group and when together will sing in tune with one another and when a male escorts a female he can also be observed signing and apparently courting the female.
These songs can last anywhere from 5 minutes to a half hour or so and then repeat over the course several hours or days. Over time these melodies and notes may change but the males will continue to sing these songs in harmony as the song continually changes. In certain instances when one male approaches another singing male they may become aggressive, territorial and defensive, which suggests that they do not like being interrupted or challenged during mating periods.
Whale songs have often been referred to as haunting, beautiful and sad by the people who have heard them. Aside from being used during mating season these marine mammals have also been observed singing during feeding periods, when they have lost a loved one or when they are feeling lonely over extended periods of time. Toothed whales are generally much smaller than their baleen whale counterparts and communicate using high-pitched clicks and whistles as opposed to the loud, long, low-pitched moans and groans of the larger baleen whales.
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