Dear /r/AskHistorians,

When I was growing up, my father told me that whenever I saw a lone magpie not in a group, it was bad luck if I didn't salute it, and also told me a rhyme that goes "One for sorrow, two for joy...". When I looked this up, I found that this is a common superstition in Britain, but couldn't find any information about the origins of these beliefs. Where does the practice of saluting magpies, and the associated rhyme, originate from?

Thank you,

Passengerpigeon.