When the Duck Hunters aren’t dropping them from the sky, ducks sure know how to fly. So do most other migratory birds, such as geese and cranes. In fact, most migratory birds know how to fly so well in that familiar V formation, military planes have followed their example for years.If you look aloft, however, and see birds laid out in the shape of a V, what’s interesting is the physics behind it all. What most people probably don’t know, is that the lead bird flies for only so long before dropping back into the pack and letting a new ...