Very early this year, but I've been swooped by a magpie in this vicinity every spring for over 5 years now. He only touch my helmet on one occasion. always comes from behind and swoops low and circles back for 3-4 more dives. They take place for about a quarter of a block. Getting off my bike and walking doesn't seem to help. I go to a parallel street Goldsmith Ave sometimes to avoid the little bugger, and twice he's even spotted me there and swooped.