While Iowans pushed their clocks back an hour over the weekend, another sign of fall is in the Iowa sky. Al Hancock, a waterfowl specialist with the Iowa Department of Natural Resources, says smaller geese have already flown south for the winter. He says they go into Missouri and Arkansas for the winter.Three kinds of geese are seen in Iowa, the biggest is called the Giant Canada goose.The eastern prairie population are often called interior geese. The small Canada goose is called a “hutchie” — and both of the smaller birds have been flying south this month through Iowa. He says the interior and hutchie typically move with the calendar at the first of October. Hancock says the “Giants” will start to fly south when snow covers the ground in Canada, Minnesota and Iowa. If there’s open water in the winter, he says some of them will stay the winter in Iowa. Hancock says no one knows exactly why the geese fly in a “V” formation, although some speculate it has to do with air drafting.