Flying in Formation

Can someone explain in layman’s terms why large birds usually, but not always, fly in a “V” formation? Small birds don’t seem to do it as much. And who decided who gets to lead the formation since the followers seem fated to follow the lead bird where ever it decided to go. Help me out here…

I’m not an expert in bird behaviour (although there are a couple on this board), but I’ll hazard a guess: The birds are arranged so as to take advantage of the wingtip vortices generated by the birds in front of them. That is, they seek to remain in the forward bird’s “updraft”. Of course the lead bird does not have a vortex to fly in; so I think the leader may fall into trail and allow a relatively “fresh” bird to take his place. Once he falls back, he can take advantage of the vortex and “fly easy” for a spell.

I read something like Johnny L.A.'s answer. There’s a sort of draft behind and to either side of each bird. In a V, all the birds but one are in a draft. They take turns leading. You will sometimes see other shapes besides the V, such as when a bird joins an existing V by starting another kink at one of the ends. We have alot of Canada Geese migrating each year here, and I often see a sort of three sided square formation.

Geese fly overhead here nearly every day. The groups are small and they go to favorite local ponds and waterways and they usually are in v or line formation of some sort. Not too many other kinds of birds take long flights in groups here. The “black bird” groups just seem to swarm around but I still can locate small groups in v shapes from time to time. The crows also group up at night and fly back to whatever sort of area they call home and these are often in some kind of line shape pattern, too.

However, the smaller birds do not seem to group up onto such large groups. A couple of these and few of those seem most likely - small woodpeckers, titmouse, cardinal, chickadee might form a group but they don’t even have the same flight patterns. I think the cardinal doesn’t go long distances in straight lines but dips down and back up in half ovals - who’d want to try and staight line fly with them?

Jois