From Mark White
Geese fly in a V-shape for two main reasons. Scientists slightly higher than the one behind it. This way, each tracked a flock of birds and discovered that flying in this one gains lift as it flies close to the bird in front, and the formation probably makes it easier for the geese to communicate and keep track of each other. It also helps them save energy during long flights. The geese don’t fly in straight lines; instead, each one flies geese take turns being in the lead. Birds’ heart rates have also been found to be lower when flying in a V versus flying solo.
Answered by Shanna Freeman for Brain Dump, How It Works issue 89