Today from the boardwalk at Piscataway Park, I watched 26 Black Terns 
flying up and down the Potomac River. It was an impressive group to 
watch as they fed close to the water, in contrast with the nearby 
Forster's and Caspian Terns which were flying much higher and diving for 
their food.

http://www.flickr.com/photos/35144142@N04/4903112602/

Some other highlights from the afternoon were 24 Forster's Terns in 
various stages of molt and 120 Laughing Gulls at the Fort Washington 
Marina, and my FOS Northern Waterthrush at Piscataway Park.

Robert Ostrowski
Crofton