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KEY TO THE BIRDS OF EASTERX NORTH AMERICA. 



Forster's Tern. Winter. 



Roseate Tern. 



Common Tern. 



Least Tern. Gull-billed Tern. 



Adult Terns (except the Noddy) have the top of the head entirely black, part of the year, varying with age 

 and season. 



