Man has used birds for direction finding for thousands of years. Bearings have been obtained by listening for over-the-horizon roosting sounds, by watching the paths of land sighting birds that, when released from the ship, circle for altitude and zoom to the first land they see, and by following the seasonal routes of migratory birds.

Among the migratory birds that piloted man is the Pacific Golden Plover (Pluvialis dominica fulva), a bird whose breeding grounds range from the Siberian tundra to Alaska. During August, September and October, the plovers, in compact, marshalled flocks, strike boldly south to winter in India, China, Australia, New Zealand, the Hawaiian Islands, Tahiti, and other South Pacific Islands.

Come April and May, the birds reverse their flight paths and head home. The lines of plovers in flight, clad in tar-black breasts and golden yellow backs, have stirred the souls of men for centuries.

The ancient Polynesians set range marks on shore in the birds' flight direction, then followed the streams of "V" formations as long as the flocks were overhead. Sometimes they were in visual range for two weeks or longer, enabling the islanders to find new, untrodden lands.

Then each year the Polynesians would already be on these new islands or "stepping stones" awaiting their winged pilots. When the plovers appeared, another voyage would begin. In time the flights of plovers helped the Polynesians spread their culture the length and breadth of the Pacific.

The plovers' Transpac flight requires maximum energy preservation, thus they fly in the "V" formation with the point in the direction of flight. Like a boat leaving a wake, the birds' movement forms an air wave toward the rear. The inboard wing of the bird behind rests on the current lift formed by the opposite wing of the bird ahead. Throughout the marathon the lead bird will come to the end of the line to rest, and birds from opposite sides will exchange positions to rest alternate wings.

It is known that migrating birds prefer flying on a beam wind. Apparently this is a navigating aid. In the fall when the migrant ventures south, the wind that prevails in the North Pacific immediately south of the Aleutian Islands is from the northwest. By heading southwest plovers migrating to Hawaii might have the northwest wind abeam until they reach the vicinity of 30' North latitude. Here they're bound to pick up the northeast trades. Changing course to the southeast enables them to fly with wind abeam until they sight the islands.