Foggy conditions early this morning made for more listening than 
seeing.  Some highlights:

Eastern Phoebes
Ruby-crown Kinglets
Blue-gray Gnatcatchers
Brown Thrasher (1)
Yellow-rumps
Yellow-throated Warbler (1 - heard only)
Louisiana Waterthrush (2)

Also, the National Park Service has put in a gravel bridge (I assume 
temporary) across the canal about 200 yards north of the lock.  Makes it 
quicker to get up to the Dierssen WMA.

A House Wren was singing in my yard this morning.

Andy Martin
Gaithersburg