Going by the reactions of my friends, choices seem to be broadly split as follows:
A. Stop whatever you are doing/saying IMMEDIATELY to utter some weirdy salutation stating with the words 'Good Morning Mr Magpie', even though it's 4.30 in the afternoon. After which your friends are permitted to resume the conversation again.
B. Deftly perform some sort of ritual involving 3 salutes and a tug on your collar without breaking conversation and still managing to keep one hand in the steering wheel/pouring hot water into a mug etc.
C. Absolutely nothing, because it's just a sodding bird and why would you?
I'm C - I think I'm the only one who is and that the world has truly gone mad 
