The Mississippi River and its floodplain are home to a diverse population of living things:At least 260 species of fishes, 25% of all fish species in North America; Forty percent of the nation's migratory waterfowl use the river corridor during their Spring and Fall migration;Sixty percent of all North American birds (326 species) use the Mississippi River Basin as their migratory flyway;The Upper Mississippi is host to more than 50 species of mammals;At least 145 species of amphibians and reptiles inhabit the Upper Mississippi River environs.