JAN., 1909. BIRDS OF ILLINOIS AND WISCONSIN CORY. 



2 93 



Bonaparte's Gull. 



Herring Gull. 



Ring-billed Gull. 



Length, 18.10 to 20.25; wm g> I 3-5 t 15-75; bill, 1.50 to 1.70; 

 greatest depth of bill, .52 to .68. 



The Ring-billed Gull is a common species in Illinois and Wisconsin 

 during the migrations and occasionally a few remain on Lake Michigan 

 all winter. A few pairs occasionally breed in Wisconsin, but the great 

 majority of them go much farther north. 



