BIRD MIGRATION THEORY MIGHT RUFFLE FEATHERS.(MAIN)

Byline: GARY ROBBINS Orange County, Calif., Register

IRVINE, Calif. -- A popular belief about the way migrating birds find their way from place to place may be fundamentally wrong, a UCI physicist said in a journal article that's likely to surprise devotees in the exacting world of bird watching.

Thorsten Ritz is challenging the idea that tiny magnetic particles in the brain and, possibly, beak of a bird allow it to read Earth's magnetic field, sharpening its sense of direction.

It's more likely that a bird's ``magnetic compass'' is controlled by little chemical changes in the brain, says Ritz, a University of California, Irvine, researcher who lays …