Meredosia Refuge serves as a temporary home to thousands of waterfowl that feed and rest on their annual spring and fall migration. When seasonally flooded the wetland Units located adjacent to Meredosia Lake provide a mix of prime habitat for diving ducks and dabbling ducks. Twenty-eight species of waterfowl are known to use the refuge. The area is also a significant area for wood duck production. The fall migration peaks in November and the spring migration peaks in late February or early March.
 

In addition to waterfowl, the low water during summer drawdowns and the resulting mudflats attract many species of shorebirds, especially sandpipers along with gulls and terns. May and August can be the best time to see many shorebird species. Dense wetland vegetation provides shelter and feeding habitat for marsh birds such as rails, herons, and egrets.
 

Due to Emiquon Refuge’s diversity of habitats, it can host over 100 species of “songbirds” at various times of the year. Significant tracts of bottomland forest support specialist species during periods of both nesting and migration. Notable species include: prothonotary warblers, red-headed woodpeckers, pileated woodpeckers and rusty blackbirds. In the drier upland forests, it is common to hear and see a different group of passerines, with thrushes, ovenbirds, and cardinals being among the more common species. Edge species, such as flycatchers, can often be seen across the refuge perched along the water’s edge.
 

Wetlands are transitional areas between land and water. They are covered by shallow water or at least for some period of time, have waterlogged soils and grow water-loving plant species which only grow in wetland areas. Many words are used to describe wetlands including bogs, marshes, swamps, potholes and sloughs. Wetlands moderate the flow of nutrients and sediment running off the land and regulate the flow of water moving downstream. They clean water by absorbing and filtering pollutants that would end up in lakes, rivers, and groundwater. They buffer riverbanks and lake shores from the eroding effects of currents and waves. By absorbing spring runoff, they take the punch out of floodwaters. Wetlands produce as much plant and animal life as do similarly sized areas of rain forest. Hydrological factors such as water depth, frequency and duration of flooding, and the amount of dissolved or suspended materials determine a wetland's functions and plant and animal populations. Other hydrological factors that affect how fast water enters and the amount of sediment it carries are partly responsible for a wetland's shape, size, depth, and even location. When seasonally flooded, Emiquon Refuge has over 1,500 acres of floodplain wetland habitat that supports a wide range of biological diversity. To learn more about the status of wetlands in the United States, see the National Wetlands Inventory Web site.
 

The protection of bottomland forests is another essential tool. Only 20 percent of the bottomland forests that once existed in the United States remain today; the majority was lost to agricultural land clearing.

Bottomland forests provide benefits to a wide variety of wildlife and fish resources. They can support up to five times the wildlife species populations as some upland habitats. Small, seasonally flooded wet areas along streams and rivers are rich in invertebrates, which serve as a food source for animals near the bottom of the food chain.

Bottomland hardwoods are valuable as roosting and den sites for many species. Some mammals, such as squirrels, use standing hollow trees as den sites, while others, like opossums and otters, use hollow trees after they fall.

Food and cover produced by bottomland forests are essential for animals like the white-tailed deer, wild turkey, and wood duck. Threatened and endangered species such as the Indiana bat also make use of bottomland forests.
 

Since European contact in North America, more than 99% of tallgrass prairie has been destroyed primarily because of conversion to agricultural uses. Undisturbed, tall grass cover is not only valuable for nesting waterfowl, it provides habitat for other species, including pheasants, grouse, bitterns, northern harriers, short-eared owls, and many passerine birds.

Native grasses have root systems between five and nine feet deep, and because of this are excellent for long-term erosion control. They also grow well on poor soil because their deep roots can gain access to nutrients and water that shallower roots cannot reach. Introduced grasses, such as brome, are more easily established and are less expensive, but the cover often deteriorates in poor soil conditions as the sod opens up and weeds invade.
Native grass stands require several years to reach maturity, and usually require mowing in the midsummer during their first and second years. Once fully established, however, there are very few weeds which can compete with native grasses for nutrients and water in the soil.