This is coming from a back yard observation and my drive by pond counts not as good as last year. It was a cold on and off this spring I found several abundant nests this year dumping up to ten eggs and not sitting. Every year is different here this year is mainly Teal not too many big ducks two weeks till go time it could change any day. Had to drain off one wet land to fill other this year the back 40 was getting dry. 17 Aug. Let me think lake water high ditch water low. Drain one wetland to fill other it's what you do. It worked I lowered the water surface of a wetland to fill other and no one has noticed yet.