This morning while walking down the drive way to pick up my newspaper, I noticed a number of birds in the adjacent bushes so I stopped and gave a low tremolo whistle (hopefully like a screech owl) and I have never seen such a mobbing before.  Within a few seconds I had the following:

Yellow bellied Sapsucker         2
Downy Woodpecker                2
Blue Jay                                 3
Northern Mockingbird               1
White breasted Nuthatch          1
Carolina Wren                         2
Carolina Chickadee                 5
Tufted Titmouse                       4
White throated Sparrow            10+
Dark eyed Junco                      3
Northern Cardinal                     3

The titmice and chickadees came within a few feet of me and the wrens and sparrows formed the next layer.  The rest stayed about 15-25 feet away, but all were constantly moving around.  After a minute or so, I continued down the drive way, picked up my paper and when I returned to the area where all the birds were, almost all had gone, just a few White throats remained.  A most interesting moment!

Winger West
Millersville, MD