![]() It's possible that blue whales are singing slightly deeper than they used to because their populations are increasing. Quite why this should be isn't entirely clear, but it may actually be good news. It is now typically about 1.5 Hz lower than it used to be - which, at the sort of bass pitch we're talking about, is roughly the difference between a natural and a flat note. ![]() For example, several years' worth of data now show that the pitch of blue whale song has been dropping year on year, since at least 2002. Moreover, studies have shown that the nature of the songs changes somewhat over time. There is, of course, some variation in this, both between individual whales and between consecutive songs. There's a particularly clear call at the 2:05 mark). (You can hear a sample here, shifted to a more human-audible pitch. The last part is about three or four notes lower than that, which is generally considered below the range of normal human hearing. The first part is commonly somewhere about the A four below middle-C, which is the very lowest note than can be produced on a grand piano. This element, termed a "Z-call" because of the shape it produces on a spectrograph, has three parts: a long, deep rumble, followed by a rapid dip and then a short, musical tone at an even deeper pitch. For the most part, blue whale songs consist of the same element repeated over and over. ![]() Like other whales, blue whales produce 'songs' that travel for miles through the deep, and, by listening to them, we can get at least some idea of where they are, and how numerous they are, and perhaps further information besides.Ĭompared with cetaceans like the humpback whale, the songs of blue whale are not particularly complex - although they remain more so than deep clicking sounds of sperm whales. There, however, are a number of different ways in which we can study them, and one of them is to listen to their calls. ![]() Yet, because, like all whales, they are not that easy to study, they remain relatively mysterious, compared with large land-based mammals. Far larger, for instance, than anything that lived during the time of the dinosaurs. The blue whale ( Balaenoptera musculus) is, as is fairly known, not only the largest animal alive today, but the largest that has ever lived. ![]()
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