By J. Dale James, Ph.D., and Andi Cooper
Many of us have used a GPS (global positioning system) to find a "duck hole" in the timber, a pothole off the beaten path, or simply an out-of-town destination
And before GPS, we depended on maps or road atlases for our navigational needs. Waterfowl, on the other hand, have no need for any of these. They've been winging their way from their breeding grounds to wintering areas and back again for eons. How do they find their way?
While our understanding of navigational mechanisms is limited by the difficulty of studying migrating waterfowl in the field, there are several things we do know. To begin, navigation during migration is primarily an extension of the homing ability found to various degrees in all birds. This ability enables birds to locate their nests or frequently used feeding and roosting sites. In long-distance migrants such as waterfowl, this ability allows them to find specific wintering and breeding sites from year to year with remarkable precision.
We also know that the navigational ability of birds is the result of both innate (genetic) and learned influences. This combination of behaviors provides birds with an extremely adaptable navigational system that can be adjusted based on their environment. This enables them to find their way remarkably well in highly variable conditions and across great distances.
The first basic element of avian navigation is orientation, or the innate ability to adjust direction. Orientation alone, however, cannot get a bird to a precise destination.
Precision in navigation—how a duck or goose gets from Point A to Point B—is generally a learned behavior, which is why immature birds get lost from time to time.