Just as surfers ride the edge of an oncoming wave, waterfowl move northward on southerly winds that precede an approaching front. Boosted by these winds, they follow major rivers from their wintering grounds to the prairie "pothole" wetlands of the Northern Plains and Canada.
Along their journey, these geese, ducks and coot stop to rest and feed on lakes, marshlands and flooded fields. The tide of the migrants peaks in mid to late March, coinciding with flood season across the Heartland, triggered by heavy rains and melting snow. It is thus a good time to visit local reservoirs and wetlands; plan to bring warm, waterproof clothing, binoculars and, if available, a spotting scope. In areas accessed by graveled roadways, using your car as a blind is especially effective when viewing waterfowl.
Diving ducks such as buffleheads, ring-necks, canvasbacks, redheads, goldeneyes, mergansers and scaup favor the deeper waters of lakes and reservoirs. Surface feeders, including mallards, gadwall, shovelers, wigeon, teal and coot are best found in backwaters or shallow wetlands. Geese rest on lakes but spend most of the day feeding in meadows and cropfields.