Vol. 24, No. 5 
Page 4 
Cooperative Waterfowl Research - W-88-R F. C. Be 11 rose, S. P. Havera, 
G. A. Perkins, H. K. Archer 
The chronology of waterfowl migration varies among different regions of 
Illinois. Aside from the inherent differences in migrational behavior of the 
various species, the length of the state and the different types of regional 
habitat affect waterfowl migration chronology. Each species of waterfowl 
migrates over a period of 2 to 3 months in the fall with the chronology varying 
among years, resulting in differences of up to 2 weeks over a span of years. 
The chronology of spring migration, influenced by the variability of spring 
weather, varies appreciably throughout Illinois and among years. 
Variations in chronology of migration by regions of the state make the 
establishment of hunting regulations difficult. Moreover, weather, water levels, 
and food conditions also add to the variables influencing local population levels. 
Our objectives during this project are to evaluate regional differences by 
species in the chronology of migration within Illinois and to evaluate yearly 
differences by species and region in the chronology of migration. Our evaluations 
will be based on 40 years of census data. 
We anticipate that the information derived from our analyses will not only 
contribute to our knowledge of waterfowl migration but will also aid in 
determining the most judicious time frame for the waterfowl hunting season. 
