Birds were sitting everywhere across the field.. .. .Ummmmm....maybe you shouldn't have been flying around at 20 ft? A good percentage of birdstrikes should not be called accidents. When you fly where birds are known to be it becomes more Darwinian than bad luck.. .. .Yesterday we were flying 500 ft just off the west coast of Canada. Copilot flying suddenly banks hard right. I look up to see a very large eagle also bank right. We roll left and dive. He (I saw proof it was a male by now <img border="0" title="" alt="[Eek!]" src="eek.gif" /> ) also rolled left and flared. The eagle, now terribly frightened and spread eagle had an H46 pass below him with about 3 ft clearance from the forward rotor. We braced for the thump of eagle on aft pylon, but heard nothing. Lucky day for all 6 of us (5 crew, 1 eagle).. .. .Lesson: Eagles own 500 and below during herring season.