Vee formation

A vee formation is the symmetric V-shaped formations of flights of geese, ducks and other migratory birds. Flying in this way aids the birds in covering long distances very efficiently by delaying the shedding of drag-inducing vortices to the birds at each tip of the formation, rather than from each bird individually. Energy efficiency can be raised by as much as 100% in this manner. The birds flying at the tip are rotated in a timely cyclical fashion so as to spread out flight fatigue equally among the flock members. The formation also facilitates communication and allows the birds to maintain visual contact with each other. Visual contact is why vee formations (and the assymetric echelon formations are also commonly adopted by flights of military aircraft engaged on a common mission.