I was at Perryville park around 3 p.m. today, and at that time Furnace Bay
was full of terns--dozens of them, mostly Forster's, but maybe some 
Common Terns as well?
I am not sure how you tell the juveniles apart. There also were at
least two smaller, darker terns, mostly gray, with brown backs.
Their tails did not appear forked. Possibly juvenile Black Terns?

Other notable birds included three immature Bald Eagles--maybe a fourth,
but I didn't get a good enough look at it--and a "generic" emp. flycatcher.


--Pat

Pat Valdata, Elkton, MD | 
"The natural function of the wing is to soar upwards
and carry that which is heavy up to the place where dwells the race of gods.
More than any other thing that pertains to the body
it partakes of the nature of the divine." --Plato