In the photo is the long side left or right of the direction of travel?
The physics answer is,
When geese do fly directly into the wind the V is likely to be the same shape and length on both sides (or of there is no wind). When they are flying at an angle to the wind, they take advantage of a second aerodynamic principle called angle of attack which in an airplane determines lift and stall speed. By finding the best angle of attack the goose saves more energy while he is flying. He will go to the side of the V where the angle of attack is most advantageous to him to fly easier. He knows which side he is going to be able to fly easier on by feeling the effects of the angle he makes to the wind. The angle on the right leg of the V is a completely different angle then the angle on the left leg of the V. Thus the right leg may support a small number of geese for a certain wind and they just feel the effects of drafting. But by changing his angle of attack and going to the left leg, the goose feels he is flying easier on that side and will stay there until the flock turns. He gets the benefits of a good angle of attack as well as the drafting. He’s simply choosing the path of least resistance.
