Humpback whale songs are truly marvelous productions. The fundamental units are notes, which are arranged in subphrases, then phrases, which are in their turn merged into themes. These are then recited, and repeated, in no particular order. The subphrases often rhyme, in what may be a mnemonic adaptation for remembering the songs, although the rhymes are not obvious to a human listener. Like a skilled opera singer, the whale steals breaths without interrupting the song; the longest recorded humpback song lasted twenty-one hours without a break, but they may last much longer. Although whale songs conform to certain rules of composition, they are not the invariable croakings of animal instinct, likes the cries of the terns above. What distinguishes humpback whale songs is that they progressively change from year to year, and all singers within acoustic range simultaneously adopt the new versions.
Why do the whales sing? No one knows, but there are interesting hypotheses. Like male canaries, male humpbacks may sing to attract, and seduce, females, which, also like canaries, may tend to favor those suitors with the largest vocal repertoires. The singers are mainly males escorting females with calves. Whale songs certainly communicate information, but the long process of correlating voice with behavior is just beginning, and the changing of songs over the years adds to the confusion. In a way, it is like burning one’s library every few years, In the still and quiet depths, away from the chop and torment of the sea surface, whale songs may travel hundreds of kilometers, and a pod, linked acoustically, may be just as extensive, the virile males declaring their vigor across hundreds of kilometers. During migration, therefore, the songs may serve as beacons, animate lighthouses in a trackless sea.
David G. Campbell
I had the pleasure of spending time with David G Campbell during a cruise to the Antarctic. I love his book and will be posting excerpts from it from time to time.
The book is called “The Crystal Desert: Summers in Antarctica” and is published by the Houghton Mifflin Company.
“A superior personal account of place, a remarkable evocation of a land at the bottom of the world” (Boston Globe)