A stroll around Constitution Gardens and the DC Veteran's Memorial produced the following:  
At Constitution Gardens there was a hunting Red-tailed Hawk.  Further on, I found several Fish Crows being mobbed by grackles, starlings, robins and blue jays.  During nesting season on the Mall, I often see groups of Fish Crows moving stealthily high in the trees.  I suspect they are looking for nests to rob, because the local breeders become very upset.  Often the crows will stand up to the mob, calling, then move on a bit, with the mob following.  Once the crazed group is a few trees away, I may see a trailing Fish Crow start to investigate the area, undisturbed.  I wonder if this is a strategy of the crow group, or just a trailing bird using an opportunity.  By the way, it is always Fish Crows that comprise these groups.  I haven't seen this behavior from American Crows on the Mall.  In any event, all the noise and commotion apparently disturbed the quietude enough that I saw no migrants.
   There were migrants at the DC Veteran's Memorial, especially several Warbling Vireos.  I also heard a Chestnut-sided Warbler and a Redstart.

Jim

Jim Felley
Smithsonian Institution