Even when they fly short distances they use the V-shape or a line and let the lead swan cut thru the air for the rest. We have been told by the locals living along the river that most the swans will leave on the same day-that day seems to be when it gets cold enough to freeze up the Mississippi backwaters and therefore eliminate their ability to dig up the bottom for food. Last year they left in the night.  What a sight it must be to see 10 to 20 thousand swans in the air at one time.  TO SEE MORE SWAN PHOTOS GO UP AND TO THE RIGHT AND CLICK ON NOVEMBER 2012.