BREEDING COMMON TERN AMONG BREEDING CASPIAN TERNS, WINDERMERE BASIN,HAMILTON,ON, 7/6/2019

   The breeding Common Tern is the smaller tern on the right.  We can ID this bird as a breeding Common Tern by it's small size compared to the Caspian Terns on the left and its completely black crown (including forehead) that extends to the nape.