Canuckbirdstrike has come up with some VERY impressive information, not just now, but on previous occasions. It makes this post almost pale into insignificance, but in respect of the original post regarding RADAR effectiveness against birds -
Having heard the folk-lore on numerous occasions I've experimentally tried zapping birds with the radar at close and medium distances, both with the 'old' high power radar, and the newer low power units. None of them had the slightest effect. (Maybe it will on future generations of genetically modified birds).
I believe that the theory originated in England in WWII when birds nesting on the stationary RDF transmitters were microwaved on the spot by the very high energy emissions. (I stand ready to be corrected on this).