Addendum to Wallace's list, mostly migrants:

HERMIT THRUSH (1 near equitation field, 1 on the path back 
through the woods from the maintenance yard), CHIPPING 
SPARROW (throughout), EASTERN KINGBIRD (1 at equitation 
field, 2 at dog run), RED-EYED VIREO plus another 
YELLOW-THROATED VIREO and BLACK-AND-WHITE (male) and 
BLACK-THROATED GREEN WARBLER at the nature center, and SWAMP 
SPARROW and COMMON YELLOWTHROAT (male) at the dog run.

Cheers,

D

-- 
Derek C. Richardson, Laurel, PG County, MD
http://www.astro.umd.edu/~dcr/Archives/Photos/birds.html