I'm no expert in radar ornithology but from doppler image at 
(http://forecast.weather.gov/MapClick.php?CityName=Gaithersburg&state=MD&site=LWX&textField1=39.1412&textField2=-77.2166) 
at 10:12 pm, it sure looks like migrating birds are running directly 
into a line of thunderstorms across Piedmont of MD.

If it is putting birds down would probably only be birds that have been 
airborne for an hour or so. Too bad it did not come through a little 
later at night when birds from further south would be passing by. Maybe 
points further south in MD will do better as the line of storms progress 
down state.

Anybody have an opinion? Maybe this is just wishful thinking on my part.

Andy Martin
Gaithersburg
apmartin2comcast.net