By CARL ZIMMER
December 11, 2007
The word “big” doesn’t do justice to whales. Humpback whales can weigh up to 40 tons. Fin whales have been known to reach 80 tons. Blue whales, the biggest animals to have ever lived, reach 160 tons — the same mass as about 2,000 grown men or 5 million grown mice.
It takes a lot of food to build such giant bodies, but how exactly the biggest whales get so much has long been a mystery. “We don’t have much of a sense of these animals in their natural environments,” said Nick Pyenson, a biologist at the University of California, Berkeley. For decades, whale experts had only indirect clues. “It’s primarily from dead animals or from a few people standing on a ship seeing whales come to the surface,” he said.
With so little information, scientists have struggled to make sense of several enigmas about the biggest whales. “It’s always been a mystery why they have really short dives for their body size,” Mr. Pyenson said. The bigger a marine mammal is, the longer it should be able to dive for food, because it has more muscle tissue in which it can store oxygen. Other species follow this pattern, but the biggest whales do not.
Mr. Pyenson and his colleagues may have solved some of the gastronomical mysteries of these leviathans by creating the first detailed biomechanical model of a feeding fin whale. In essence, they have created the world’s biggest gulp.