Lack of consistently cold winters and ice up North for over a decade, excess food on the ground in those areas and a migration South that never occurs. We all know that ducks imprint and fly where they were taught to fly. If over several generations of ducks, significantly fewer fly to North AL or Mobile Bay and a younger generation doesn't imprint, won't they eventually quit showing up in our part of the world? Only thing that reverses this is a few long, sustained winters with extreme cold and ice in the upper Mid-West. Doubt that will happen.