Vol. 2k, No. 7 
Page 5 
Bald eagles began leaving for their breeding grounds in early .March this 
year as evidenced by sudden increases in the numbers of birds observed in 
northern Illinois. The exodus was completed rather abruptly; by the last week 
of March, only a few stragglers were observed. Thus, the aerial waterfowl 
censuses provide a unique opportunity to monitor population changes of endangered 
bald eagles while they overwinter in Illinois. 
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