You might wish to read the CAA article with care. It clearly states that there is no scientific evidence to support the use of radar as an aircraft bird hazard deterrent.
I have been closely involved in bird hazard research for a number of years including researching, validating writing five chapters and editing a book on bird strike information for Transport Canada, titled "Sharing the Skies" available to read on-line at
www.tc.gc.ca) I can assure you there is no data to support the use of weather radar and the low power output of aircraft weather radar is too low for birds to detect. I researched all available material and spoke at length with experts in the field of bird biology and radar and they clearly confirmed that with low power output and the understanding of bird sensory capabilities that that it is highly unlikley that they can sense radar, mucch less understand what to do about it.
This is essentially an urban legend that may heave been fostered many years ago from anectdotal information from pilots of military aircraft that used early fire control radars that operated at significantly higher power outputs than current weather radar.
Richard Sowden
A320 Pilot & Bird Strike Researcher