They were so loud, this author heard them from inside. At first, their honking seemed like just a bunch of chaos. But the longer one listens, there appears to be an obvious excitement going on with them. Why are they doing that while flying? I was so mesmerized with their organized chaos chatter, I almost forgot to go get my camera to snap a few photos before they were gone.
Online information from a blogger under the name of Christian Personal Finance indicated scientists think the honking has two effects on the entire flock. First, it allows the geese to know where each other is, to avoid hitting one other. Secondly, it is commonly believed honking is a way of encouraging one another, to keep up flock morale. By honking, geese are able to communicate their mutual success, and really put forth a full effort for the entire flock.
Geese that travel together "in formation," or in the shape of a V, are able to travel between 75 percent to 80 percent farther than a single goose traveling alone, according to online sources.
By traveling this way, geese maximize the amount of energy that gets output from each goose during flight. The goose in the front creates a slipstream for which the geese following can pass through, creating less drag on the overall group. The geese behind help to push the geese in front of them when they push their wings up, because it creates an upward draft that lunges forward. The effect is similar to a push-pull motion, that helps all flock members.
The lead goose uses more energy than the following geese, and so gets tired much more quickly. To mitigate this problem, the lead goose position is rotated among all members of the flock, so that each goose takes the lead position, but then gets to rest before taking the lead again.