Whales Eat Three Times More Than Previously Thought

As whales continue to rebound, their role in recycling nutrients should reset the nutrient cycle—and boost krill—once again, he says.

‘Better than nothing’ 

To estimate how much baleen whales eat, scientists previously analyzed their metabolic needs based on their size and activity level using a closely related or similarly sized animal as reference. For instance, by measuring how much orcas (or killer whales) eat, biologists extrapolated what a humpback whale or a blue whale would consume.

“When you get down to the behavior, ecology, and physiology of these animals,” Savoca says, “a blue whale and a humpback are very, very different from a killer whale.” He allows that the earlier attempt is “better than nothing, but it’s not actually a very good guess at all.”

For their investigation, Savoca’s team tagged 321 whales spanning seven baleen species: humpback whales, blue whales, fin whales, bowhead whales, Antarctic minke whales, Bryde’s whales, and North Atlantic right whales. (Watch the world’s biggest animal lunge for its dinner.)

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Savoca describes the tags—devices equipped with accelerometers, magnetometers, GPS, light sensors, gyroscopes, and cameras attached to the backs of whales with special glue—as “whale iPhones.” Just as our phones can tell us how many steps we take in a day, whale iPhones can measure how many lunges a whale makes and at what depths. Baleen whales often catch food by lunging, or accelerating through the water in quick bursts, horizontally or vertically, with mouths agape.