Edward Lukaszewicz, age 12, of Peterborough, Ontario, Canada, for his question:

Which goose leads the V-formation?

Bird watchers used to think that the flock was led by a wise, old goose who knew the way there and back. From his position at the head of the V formation, the less experienced birds spread out and followed his lead in two neat lines. Now we know that this is not so at all. Most likely any goose knows the way, even the young ones who have never migrated south before. What's more, careful watching revealed that the lead goose is not always the same bird. From time to time, he drops back to a position in line and another goose takes his place.

The reasons why the squadron takes the V formation may be related to the dynamics of air currents. Streams of air flow freely around and over the V shape, much like the air flow around a streamlined plane. Cutting, through the air in front of the V requires the most energy. Therefore, the resistance of the strong air flow is lessened for the rest of the geese due to the extra effort put forth by only the one. After a while, a travel weary lead goose drops back to rest, while another one takes a turn at the tough job.