Short stopping isn't the same as back in the 60's & 70's when water was kept artificially open by state agencies and bait was also placed for the birds as well. Today, drive up through the plains states and you will observe bazillions of acres of grain. Warm water discharge from power plants along with a trend of milder winters has also been a factor in migration changes. Ed is spot on with his comments on mallards in Kansas along with the post on mallard limits east of KC. Why? Look at where the snow line is located. If they cannot get to the grain, they will fly to where the snow isn't. If you are a traveling waterfowler, the snow line should be your primary destination point. If you are a stay at home waterfowler and are looking at empty skies, the snow line is why.