Common Terns in McLean County, IL

On Wednesday, September 30, I stopped by the Gridley Wastewater Treatment Ponds after work, and I was surprised to find a Common Tern. I had recently seen my lifer Common Terns at Carlyle Lake earlier in the month, but this was my first Common Tern in McLean County. Common Tern is a difficult bird to see in McLean County. I had seen many Caspian, Forster's, and Black Terns, but no Commons. Here are a few photos of this bird, but has a dark carpel bar, a long black-tipped bill, and a primaries extending past the tail.







The next day after work, I stopped by again, but the Common Tern was not there. So I decided to check the buoys by the water pump house at Evergreen Lake. On my way to Evergreen I remembered the buoys by the spillway at Lake Bloomington. So I stopped there first and found another Common Tern. This one did not have dark carpal bars yet, but face pattern and long primaries ruled out Forster's, while the bill length and dark primaries ruled out Arctic.