Terrestrial Communities 



Waterfowl 



Pools 24, 25, and 26 are the most important navigation pools on 

 the entire Mississippi River for the mallard, the most abundant duck 

 in the Mississippi flyway. Pool 19 is the most important navigation 

 pool for lesser scaups, and next to pool 8, also contains the largest 

 concentration of canvasbacks in the Midwest. 



Private duck clubs abound laterally to Pools 24-26, and are es- 

 pecially prevalent adjacent to Pool 26 in St. Charles County, Missouri. 

 Extensive public shooting grounds occur in Pools 25 and 26, but only 

 small areas are utilized for public hunting in Pool 24. Refuges have 

 been established by the U.S. Fish and Wildlife Service in Pools 25 and 

 26, and adjacent to Pool 24. 



Impounding the Mississippi River with navigation dams that created 

 navigation Pools 24-26 generally enhanced waterfowl habitat by creating 

 many thousands of acres of shallow water. The addition of refuges in 

 the impoundments added greatly to the assets of the pools both for 

 waterfowl occupancy and waterfowl hunting (Bellrose, 1954: 169). 



Bellrose et al. (1977: C46) indicated that the abundance of vari- 

 ous natural food plants in the Illinois River valley was correlated 

 to the amount of time spent in the valley by certain species of water- 

 fowl. The pintail showed an increase in density as the abundance of 

 moist soil and marsh food plants increased. The wigeon's use of the 

 valley correlated with increased aquatic plant production. Green-winged 

 teal abundance increased as the abundance of all waterfowl food plants 

 increased. 



Moist soil plants currently constitute the majority of natural 

 waterfowl foods in the project area. They volunteer on exposed mud 

 flats during the summer and must be inundated by 0.5 to 1.5 feet of 

 water in the fall to enable waterfowl to feed upon the seeds produced. 

 Moist soil plants are especially sensitive to pool levels early in 

 growth when inundation will drown them. Many of the duck clubs, federal 



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