This vibrant colored duck is well adapted to living in the Mississippi River floodplain forest. Although it may be visibly seen in the open water, the wood duck mysteriously disappears in the shadows under the forest canopy. If you listen closely you may hear the rustling of leaves, which may be wood ducks searching for buried acorns that have fallen from the oak trees. Wood ducks are agile navigators that can maneuver through the robust floodplain forest. Unlike a lot of other waterfowl, wood ducks are cavity nesting birds and the most abundant species of breeding ducks on the refuge. The females search out hollows in trees that were made from other animals such as woodpeckers and squirrels, in order to lay their eggs out of the reach of most predators. In early summer the young wood ducks hatch and must leap down from the nest. The ducklings then spend the rest of the summer foraging among the backwater lakes and sloughs on invertebrates and floating vegetation, such as duckweed. In late fall, wood ducks leave the refuge and migrate south to winter and begin the courtship process that will eventually lead them back to the refuge the following spring.

If you visit the refuge in fall, it is very common to see a raft (large group, possibly hundreds of thousands) of canvasback ducks stretching for miles near Ferryville, Wisconsin. The canvasback is a duck that forages by diving to the Mississippi River bottom and grubbing out the wild celery tubers, a nutrient rich enlarged part of the plant. Other common diving duck species on the refuge are the lesser scaup (commonly referred to as bluebills), common goldeneye, ring-necked duck, bufflehead, ruddy duck, and mergansers (hooded, and common). Their wings are relatively small compared to their body size, so divers must use rapid wing beats when they fly, and when launching into flight, most of this group patter along the water before becoming airborne. Divers have large feet, placed well back on the body and are not agile on land. They dive, sometimes to great depths, to feed on aquatic plants, fish, clams, and snails. Favorite diving duck foods on the Upper Mississippi River are wild celery tubers, sago pondweed, fingernail clams, and snails.

The Upper Mississippi was a free-flowing river until a series of locks and dams were constructed in the 1930s to provide a constant 9-foot navigation channel for commercial barges. This changed the habitat of the river into pools and created three major habitats known as the braided stream habitat located in the upper portion of the pool, the backwater marshes located in the center portion of the pool, and the open water habitat located in the lower portion of the pool. All three zones provide distinct habitats for the refuge’s wildlife. The braided stream zone resembles the river prior to lock and dam construction with its narrow cuts and channels that snake between islands of floodplain forest. Here you might see wood ducks, woodpeckers, beaver, or an elusive river otter.

The shallow waters of the backwater marshes cover land that used to be hayed before the lock and dams were here. This habitat supports the best marsh habitat and is the haunt of puddle ducks, muskrats, bass, and panfish.  Many backwater areas are preferred breeding and nesting areas for species sensitive to certain human disturbance.  The more remote areas of the refuge are an important component of the river refuge experience for many visitors. Floating logs and fallen trees provide perfect basking locations for eleven species of turtles including the painted turtle.
 

Prairie habitat is generally uncommon in the floodplain, but there are several areas that occur on islands and sand terraces adjacent to the floodplain. In the southern end of the refuge the Lost Mound Unit near Savanna, Illinois contains a seven-mile long sand dune along the river's edge and thousands of acres of sand prairie and oak-savanna habitat. The Thomson Prairie area 25 miles down river from the Lost Mound unit protects similar habitat. These units contain some of the last remaining habitats of their kind in the state of Illinois. Prescribed burning is one of the management tools used to conserve these special sites and the rare plants they contain.