A rather spectacular number of birds in Rock Creek Park, DC, this morning -- although the increasing leaf cover (is it early this year or just my imaginat- ion?) made it difficult to see everything. We had very large numbers of both warblers and thrushes, including three Grey-cheeked and many singing Swainson's and Veeries. 18 species of warbler with highlights being Wilson's and Tennessee. Unfortunately the male Mourning Warbler seen yesterday in the Maintenance Yard (not by us, alas!) was not around. We also had a bright male Blue Grosbeak in the Maintenance Yard. Yesterday we did Layhill Park in Colesville, MD and had both Bobolink (which is unusual "down-county") and a Lincoln's Sparrow. Gail Mackiernan and Barry Cooper