Did you ever get an answer to why the hawks do this? I'd be really 
curious to know, too.

June Tveekrem
Columbia, Howard Co, MD
tweekiebird AT toadmail DOT com


Chris Barnard wrote:

area around Dulles Airport...
some of the hawks in the vicinity have placed stones(about 2 inches 
or so long, round, smooth stones) on top of the flat surfaces on the 
top of the lights on the light pole.

Chris Barnard
Rockville, MD