Bill Butler and I spent a few hours this morning at the Maintenance  
Yard and saw the following:

Black-throated Blue Warbler (2 female)
Palm Warbler (2)
Common Yellowthroat (3)
Yellow-rumped Warbler (10+)
Blue-headed Vireo (2)
Ruby-crowned Kinglets (~20)
White-throated Sparrow (10+}
Song Sparrow (many)
Chipping Sparrow
Junco (15+)
Sharp-shinned Hawk
Red-shouldered Hawk (heard)

Wallace Kornack
Washington DC