Marine predator performs underwater acrobatics for best chance at catching a meal

By Susan Milius

Web edition: November 28, 2012

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ROLLING IN THE DEEP

Blue whales sometimes roll belly-up before lunging at their lunch, a new study suggests.

Credit: © Ari Friedlaender

To catch a skittish lunch, blue whales roll their massive bulk over and do a belly-up lunge if that’s what it takes.

Video cameras and high-tech tags stuck to whales’ backs revealed the underwater acrobatics that let the world’s largest living predators survive on some of the tiniest prey, says Jeremy Goldbogen of the Cascadia Research Collective in Olympia, Wash.

Blue whales manage to grow to about 30 meters in length (longer than two school buses put together) just by opening their huge gapes and lunging to engulf mouthfuls of seawater and whatever creatures are swimming in it. It’s a diet based on soup, and it sustains a whale of a body only if the lunger nabs a dense school of prey.

Sticking instruments on 22 blue whales off the southern California coast let Goldbogen and his colleagues study dining styles, including 44 rollovers. During a lunge, the maneuver could position the whale’s mouth for the best gulp. Between lunges, rolling over may provide a panoramic scan of what to swallow next, Goldbogen and his colleagues report November 28 in Biology Letters.