Most ducks, geese, and cranes migrate to warmer climates as temps in their natural habitats drop, so by the time the lake is frozen, they've been long gone. That's why in the southern states, duck/goose hunting season starts in the early autumn, because of the sudden influx of huge numbers of birds that have left Canada and the Northeastern U.S. and moved to the warmer gulf coast marshes, and other waterways.