voi. 23, no. io 
Page 5 
floods, numerous waterfowl refuges have been established in Illinois. The 
recent creation of power plant cooling lakes and flood control-recreation lakes 
has provided waterfowl with new habitat. The effects of climate, weather, 
refuges, and cooling lakes on waterfowl distribution, abundance, and chronology 
of migration needs clarification. 
To answer such questions, we will analyze census data that have been 
collected by the Natural History Survey. Fall waterfowl have been censused in 
the Illinois River valley for 41 years, in the Mississippi River valley for 3*4 
years, in southern and south-central Illinois for C years, and in northeastern 
Illinois for k years. Winter waterfowl censusing began in 19^9. Spring water- 
fowl censuses have been collected in the Illinois and Mississippi valleys for 
17 years. These data will be placed on computer tapes and interpreted. 
Examination of this wealth of census data should contribute to future 
management strategies by helping us evaluate Illinois' role in the waterfowl 
resource each season, select the wisest time for the waterfowl hunting season, 
and establish or enhance waterfowl refuges in critical areas. 
