Air Date: Week of March 9, 2001

Transcript

VILLIGER: Humpback whales look like the pimply teenagers of the marine world. Big lumps called "tubercles" bulge out all over their head and fins. Some range up to six inches across. Humpbacks are the only whales with tubercles, and scientists have long wondered why. Now researchers say tubercles on the leading edge of the whales' fins help with maneuverability. That's important since humpbacks need to make tight about-face turns when hunting prey. In lab simulations, it seems these tubercles increase lift, which is the buoyant force of the water pushing upwards. The bumps also decrease drag, which is the force of the water pushing backwards. Engineers are experimenting with bumps modeled on the humpback tubercles to make airplane wings and ship rudders more maneuverable. That's this week's animal update. I'm Maggie Villiger.

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CURWOOD: And you're listening to Living on Earth.