Two flocks of geese went over my house last night, honking. I don't know why they do that; surely it would be more efficient to fly quietly? Maybe it's something for the beginnings and ends of flights, or when they're about to make a sudden direction change, to make sure the flock stays together. The flock I saw was Canada geese; I don't know about the other.
There's something very autumnal about the sound of wild geese, even though they migrate in the spring too. It makes me want to go stand on a windy cliffside overlooking the moors, or something similarly romantic and impractical. Certain kinds of weather will also set off this desire; it's not just the geese.