You have probably seen a flock of geese or other birds flying in a V-formation and wondered why they do so. Scientists at the Royal Veterinary College, UK have cracked this mystery based on hours of data logging from small transmitters fitted on bald ibises, a critically endangered species.
It turns out that the wind behind the lead bird and off to its side is pushed upward which is used to its advantage by another bird that follows the lead bird closely. Thus every bird that follows behind another one is getting a free lift every so often resulting in a pattern. This allows them to conserve energy during long flights which the birds undertake.
This remarkable work has been published in Nature and more about it can be read here .