Four million ducks fly over the Confluence of the Mississippi and Illinois Rivers, and the Confluence of the Mississippi and Missouri Rivers a few miles downstream.
There are plenty of geese in Illinois this fall and winter, but the geese will make do with a golf course. Ducks need wetlands and Illinois wetlands were short on ducks this fall and winter. The early freeze didn’t help either.
Too much rain last summer kept mudflats underwater; moist soil planats did not germinate; Hurricane Ike reflooded the rivers in the Fall.
The wildlife refuges along the Mississippi and Illinois rivers manage moist soil units, which are bound by levees, for the growth of wetland plants. Water control structures set in the levees allow refuge managers to fill and empty the ponds.
Managers empty the ponds in June to seed the ponds with wetland plants or to allow dormant seeds to germinate. The drawdown also allows wading birds, herons and rails, to come in and patrol the mudflats for crawdads, and crawdads to borrow in the mud and breed.
Slowly, over the course of the summer they raise the water levels in the ponds, while being sure to keep the growing tips of the plants above water. Then, in the fall, as ducks are migrating south, they empty the ponds, and invite the ducks to feed.
If, as was the case last summer, the mudflats along the rivers, those in the batture lands between the levees and the river, were flooded for the better part of the summer, and then reflooded in September and stay flooded until mid-October, drowning whatever plants managed to grow, the ducks arriving later in the fall found slim pickings.
Those refuges on elevations above the river or laid out behind the river levees were able to provide foraging habitat for ducks, but these were hit by the early freeze in December.
For more information go to http://blogs.suntimes.com/bowman/2009/02/tough_2008_for_illinois_waterf.html.