The blue whale holds the title of largest creature that has ever lived, and it may also be the most mysterious. The biggest blue whales can outweigh every player in Major League Baseball and the National Hockey League combined. Their mouths can gulp more than thirteen thousand gallons of seawater. A newborn can be over twenty feet long and gain nearly twenty tons in seven months—about eight pounds per hour. Blue whales emit more powerful sounds than any other animal on earth, though many of their vocalizations are beyond the range of human hearing.
Yet nearly everything that we have learned about blue whales has come after humans almost wiped them out from the oceans. A century ago, some three hundred thousand roamed the seas. But in the first decades of the twentieth century, humans hunted and killed 99.9% of them. Their numbers decimated, the species seemed destined for extinction. Only in recent years has the number slowly begun to increase, along with hope for the blue whale’s future.
Equal parts history and science, Wild Blue is the first comprehensive portrait of the blue whale. It draws upon new findings from scientists who have begun to identify individual blue whales and understand how they dive, how they feed, where they migrate, and why they emit their haunting, low-frequency calls. With deft, poignant writing, Dan Bortolotti gives us the most vibrant, breathtaking view to date of these magnificent creatures.
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Dan Bortolotti has published seven books of nonfiction, including Hope in Hell: Inside the World of Doctors Without Borders, and has twice been nominated for the Science in Society Book Award, given by the Canadian Science Writers’ Association. His writing has appeared in more than two dozen magazines in North America. He lives with his family just outside of Toronto.Excerpt. © Reprinted by permission. All rights reserved.:
Into the blue The blue whale is at once the largest animal in the world and one of the most mysterious. It is the longest, heaviest and loudest living creature, and yet it can be remarkably inconspicuous. Only a tiny percentage of people will ever have the good fortune of seeing or hearing one in the wild. Humanity’s attitude toward blue whales is also full of contradictions. Ancient cultures, so far as they knew about the mightiest of sea creatures, mythologized them. Modern humans, by contrast, chased them to the bottom of the globe, blasted them with exploding harpoons and rendered hundreds of thousands of them into soap and margarine. Today, the blue whale’s place in our world has come full circle—once again held in awe, yet still little understood. Perhaps the misunderstandings should not be a surprise. After all, the blue whale’s dimensions are so gargantuan that humans have a hard time comprehending them. If someone told you that the sun’s core temperature approaches 15 million degrees Celsius—which is true—would that figure have any real meaning? If another description increased the number by a few million degrees, would it seem any more implausible? The same issue seems to come up when describing blue whales: the animal’s physical characteristics are exaggerated, often to the point of absurdity, yet we don’t immediately notice. Many books and articles, for example, state that blue whales can be over 110 feet—a few stretch this to 115 feet—which almost certainly isn’t true. The 2007 edition of Guinness World Records tells us that a blue whale’s heartbeat can be heard up to 19 miles away, which is nonsense—no one has ever heard a blue whale’s heartbeat, let alone from that distance. Others claim that blue whale calls are as loud as jet planes, heavy-metal concerts, even undersea earthquakes, and that blue whales routinely communicate across thousands of miles of ocean. Their diet, according to the venerable National Geographic, is up to 8 tons of krill per day. Think about that for a second: 16,000 pounds of food in 24 hours. All fantastic tales, to be sure, and all inaccurate, unproven, or at the very least highly misleading. It is as though the truth about blue whales wasn’t astounding enough. The truth is astounding, and it doesn’t need to be stretched. Blue whales are indeed the largest animals ever to inhabit the earth. Once in a while, someone asserts that the mightiest dinosaurs were larger, but until there is a reliable method of determining a dinosaur’s weight from a fossilized skeleton, this is pure speculation. Granted, a few dinosaurs may have been longer from tip to tail—although the longest scientifically measured blue whale was 98 feet, while the longest complete Diplodocus skeleton is less than 90 feet—but no prehistoric species has ever rivalled the blue whale’s mass, which likely exceeded 200 tons in the burliest individuals. The vast majority of blues never reach these dimensions, of course—most today average about 70 feet and weigh perhaps 70 tons, while those in the Antarctic are typically about 80 feet and 100 tons. By comparison, only the heaviest African elephants weigh more than 6 tons. Roger Payne, the pioneering American scientist who has lived among whales for more than 40 years, vividly recalls the first blue he ever encountered: "Although by then I had probably seen as many whales as anyone alive, this creature made me feel I had never seen a whale at all."1 One might think that an animal so large would be thoroughly understood by scientists. But of all the popular misconceptions about the blue whale, this may be the most glaring. We live in a world where scientific discoveries are often so remarkable, and so far removed from our everyday experiences, that they give the instead, they have a series of flexible, bristled plates called baleen, which they use to strain prey from the sea. The size and shape of these baleen plates varies radically—from less than 8inches to more than 10 feet—as each species has adapted to its preferred type of prey, whether fish, copepods or tiny shrimplike crustaceans called krill. While some baleen whales feed on a combination of these, blues are the pickiest of eaters and prey almost exclusively on krill. The two groups differ in other ways: odontocetes have a single blowhole, while mysticetes have two. Male toothed whales also tend to be bigger than females—in the case of sperm whales and orcas, the difference is extreme. In baleen whales, however, females are larger. Odontocetes also use a sophisticated form of sonar to locate their prey, sending out high-frequency clicks and whistles and listening for their echoes, much as bats do when foraging in the dark for insects. Baleen whales also have a complex repertoire of sounds, as we will explore in detail, but they do not use them for echolocating prey. The baleen whale suborder is diverse, but with a few exceptions, it is made up of giants. Right whales and bowheads, the first to be targeted by European whalers more than a thousand years ago, reach 50to 60feet. The little-known pygmy right whale, found only in the southern hemisphere, is about a third as long. Grey whales get as large as 40 to 45 feet. All other baleen whales are lumped together in the family Balaenopteridae and are known as rorquals. Their most obvious identifying feature is the series of grooves that extend some two-thirds of the way along the ventral surface, or underside, of their body. These pleats allow the animal to expand its mouth into a cavernous pouch—somewhat like a pelican or a bullfrog—thereby taking in vast quantities of water and prey. This evolutionary adaptation, as it turns out, was key to these animals becoming the largest inhabitants of the ocean. The origin of the word rorqual is unclear. The Norwegian ro/r means groove, tube or channel, while hval means whale. Many popular sources, reasonably enough, say the word means something along the lines of "grooved whale," a reference to the throat pleats. Most dictionaries disagree, however, and some trace the first syllable to an older Norse word for "red." While it seems odd to describe rorquals this way—each species is some combination of black, grey, blue or white—there may be an explanation. The ventral pouch is light coloured, and when extended it can take on a pinkish appearance as it gets flushed with blood. Whatever the etymology, the rorquals include at least seven species. The oddball is the humpback whale (Megaptera novaeangliae)—its gigantic white-bottom pectoral fins, rounded body and the bumpy tubercles decorating its head are unique. The remaining rorquals are all classified in the same genus, Balaenoptera, and are similar in appearance, differing mainly in coloration and size. If a non-specialist were to look at silhouettes of all six with no indication of the scale, the species would be almost impossible to identify. In addition to the distinctive throat pleats, they have smooth and streamlined bodies and a small dorsal fin located close to the tail stock. The smallest and most abundant rorqual is the minke, usually divided into two species: Balaenoptera acutorostrata in the northern hemisphere and B. bonaerensis in the Antarctic. Minkes are typically 23 feet in length and were once considered far too small to be worth hunting, though today hundreds are killed annually by Japanese and Norwegian whalers. The Bryde’s whale (B. edeni), a tropical species reaching 49 feet, is the least understood rorqual, as it has never been hunted in great numbers. The slightly larger sei whale (B. borealis) is found in all oceans, usually at mid-latitudes, though it too was hunted in the Antarctic. The second-largest rorqual—and the second-largest animal on earth—is the fin whale (B. physalus), or finback, which is commonly 62 to 65 feet, though the largest females may exceed 85 feet. Finally, there is the grandest of them all—the blue whale (B. musculus ), which averages 69 to 72 feet outside the Antarctic. In the Southern Ocean, whalers took individuals that exceeded 98 feet and may have weighed as much as 200 tons. The rorqual species are so closely related that they occasionally interbreed. Researchers in the North Atlantic have seen individuals that resemble both blue and fin whales on many occasions, and of southern Chile. They reliably visit waters off southern and western Australia, Indonesia and Madagascar; in the north-central Indian Ocean they occur off eastern Sri Lanka and the Maldives. Finally, about 2,000 blue whales still roam the Southern Ocean, all that is left of a population that once numbered about 240,000. Researchers today visit many of these feeding sites annually to conduct surveys and compile catalogues of individual blue whales. The first continuous blue whale study, however, was not launched until 1979, when the American biologist Richard Sears started his work in the Gulf of St. Lawrence, and later expanded his study area to other parts of the Atlantic. The thriving population of blue whales off California appeared rather suddenly in the mid-1980s, and those in southern Australia and Indonesia were poorly known to science until the late 1990s. The rediscovery of the feeding ground in southern Chile—it had formerly been known to whalers—was announced with some fanfare in 2003. As for the blues off Madagascar and Sri Lanka, they remain largely unstudied. Blue whale research is conducted almost entirely in summer, and not simply because the weather is more amenable—there is also the nagging problem that no one is sure where the animals go in the fall and winter. Like the s...
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