|It's not just for the skies.|
When I went looking for a photo (or even a mention) of geese using this formation on the ground, I found nothing. I was surprised. You'd think there would be photos or a discussion of this somewhere. Perhaps I used the wrong search terms.
In any case, what they do is the following. When a predator lands on the ground in territory that the geese consider theirs, they step into V formation. It's just like the one pictured above but it takes place on solid ground. What they do is approach the threat as one unit, a huge, V-shaped monster. It seems to the predator that he's being "surrounded" as the lead goose's aggressiveness is amplified by the two arms of the phalanx.
The geese on our property, perhaps 20 or 30 of them, did this to a turkey vulture the other day. They marched in a well-formed V, with heads held low and necks extended far forward in threatening fashion. And they made lots of noise as they approached, so they presented not only a visual but an auditory wall of hyped-up geese.
Worked like a charm. The turkey vulture flew off and didn't return. I will definitely try to get a photo the next time this happens. Birds are so cool. By the way, this is exactly what Konrad Lorenz pointed to in his book, "On Aggression". In the animal world, aggressive displays are a way to funnel aggression into activities that allow the creatures to express the feeling of aggression while protecting their territory and causing no harm to themselves -- or even to the predator for whom the display is intended.
This is a talent humans must develop. We don't need to obliterate countries and people. Instead, we could learn to channel our aggression into non-destructive displays such as sports. Have a beef with another country? Play a soccer match to decide who wins. Preen and strut and threaten all you want -- year-round if it makes you happy -- but in the end, only play an aggressive game. The geese have this all worked out. So do fish and a zillion other animals. So how come we can't manage this simple trick?