Parkinson's petrels: diving for dinner.

A clumsy seabird called the Parkinson's petrel can't com- pete with its more agile peers that catch leaping fish in midair. Rather than starve, this petrel has developed an unusual foraging strategy, one that involves a close relationship with two rare species of dolphins.

In the most recent issue of THE CONDOR (vOl. 94, no. 4), Robert L. Pitman and Lisa T. Ballance of the Southwest Fisheries Science Center in La Jolla, Calif., describe the petrel's tactic of diving for its dinner.

These seabirds breed on two islands off the coast of northern New Zealand during the summer and spend their winters in the eastern tropical Pacific Ocean. During 28 research cruises, Pitman and his colleagues discovered that Parkinson's petrels regularly associate with two rare marine mammals: false killer whales and melon-headed whales. (Because of their large size, these mammals are referred to as "whales" even though they are actually dolphins, Pitman says.)

The Parkinson's petrel preferentially follows herds of false killer and melon-headed whales. Once these dolphins catch a squid or some other large prey, the petrels dive into the water searching for scraps, Pitman says.

That's an unusual strategy for a seabird, comments marine biologist David Ainley of the Point Reyes Bird Observatory in Stinson Beach, Calif. Most seabirds follow schools of fast-swimming tunas that drive fish to the ocean surface, he notes.