This is a Black Tern
There were a few pairs nesting near the boardwalk at Point Pelee
And are extremely protective of their nest
They kept swooping down at Sharon and I as we walked the boardwalk
We captured a few images of them and went on our merry way
We did not want to stress the birds too much.

Click on the image below to see the alternate PAD photo for today; the female Black Tern with the egg they were guarding.