Researchers’ puzzle: How do grebes walk on water?

  • Fri May 11th, 2012 9:46pm
  • News

Associated Press

KLAMATH FALLS, Ore. — A Harvard graduate student has brought a team of researchers to Upper Klamath Lake in southern Oregon to try to figure out how grebes manage to walk on water.

Sex may have something to do with the phenomenon called rushing, in which the birds race upright across the water by taking five to 20 steps a second.

It’s often part of a courtship ritual.

But little is known about how the bird is able to generate the force to propel itself, researcher Glenna Clifton told the Klamath Falls Herald and News.

“Part of this work is being able to understand what aerodynamic forces go into this movement,” she said. “This could be used to design robotics that could walk on water.”

The grebe doesn’t use its wings for propulsion, instead lifting and tucking them behind its back. That leaves the entire responsibility of locomotion on the grebe’s feet.

Clifton and two team members train two high-resolution cameras shooting from different angles at 325 frames per second on the Clark’s and Western grebes.

They have only seconds to record the displays, and there can be long intervals of inactivity.

“I sit here for two or three hours with no activity, just banging my head against the wall to keep myself awake,” Clifton said. “When it happens, you have such little warning.”

The researchers have been working along the shore near a marina on the lake at Klamath Falls for the past two weeks. Clifton plans to begin examining the data and working on a paper after May 21.