A little late on this:

Twice this week (MON & TUES) YCNHs were seen on the railing of the concrete "pond/spillway" in front of bldg 21 in the morning. This is the area where the creek re-emerges (from who knows where).  In addition on Monday a second YCNH was seen perched nearby in one of the dead trees at the edge of the creek and parking lot and above the smallish Mulberry trees.

Jim (Michael) Speicher
jugornought—at—yahoo-dot-com
Bethesda @work :(
Broad Run_S. FRED Co @home :)