大象传媒

Swans have a problem. Being one of the heaviest of all flying birds, just getting into the air is a struggle that requires a lot of energy. Once they are up in the air it is all about saving energy and that is why they fly in formation. By sticking close together, each bird gains a little extra lift from turbulence created by the bird in front. This is enough to make a 50 per cent energy saving.