I think sometimes one leg is longer and sometimes it isn't.
Canada Geese are graceful and smooth in their flight, appearing to glide through the air with easy and assurance. They fly in a loose, ever changing V-shaped formation, close to one another so that they may advantage of the slipstream effect of the bird ahead. The U.S. Air Force learned how from the wild goose. Flying in a V formation greatly reduces air resistance for both military planes and birds, allowing them to fly 71 percent further in formation than they could do otherwise. By positioning itself slightly to one side of the bird ahead, a goose, gets lift from air currents coming of the wings tips of the bird ahead. It is thought that the dominant gander of the flock leads the migration flight south in the fall. On the spring migration flight back, there is evidence that the dominant gander's mate leads the flock on the final leg of the flight to the nesting site.
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When a goose falls out of formation, it suddenly feels the drag and resistance of flying alone. It quickly moves back into formation to take advantage of the lifting power of the bird immediately in front of it. When the lead goose tires, it rotates back into formation and another goose flies to the point position. The geese flying in formation honk to encourage those up front to keep up their speed.
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http://www.cambron.com.au/index.php/about-us/the-geese