A study done sometime back also shed some light on this particular V formation. This study discovered that birds flying in a V format had lower heart rates than bird flying alone. Why? The aerodynamic V shape formation reduces the air drag (air resistance) that each bird experiences when in flight in comparison to a bird flying solo. This allows them to cover longer distance (thousands of miles) with much less effort.
There are other benefits of flying in this V position. Every bird in the group fly in the field of vision all other members. This helps in keeping track of each other in the group. This also makes it conducive to the members in the group to communicate with each other while in flight. For example, if one bird should become sick or has been injured by some means such as being shot, then, that bird will fall out of formation. This will then result in two other geese falling out with the wounded goose to help and offer protection and will remain until that bird recovers or dies before rejoining the others.