As I went up one side of a street today, I noticed a moose eating on the other side of the street. As I was coming back down his side of the street, he seemed to be watching me a lot more intently than feeding moose usually do. I crossed back to the first side and kept coming, but each step I took was matched by a step towards me by the moose. I retreated a little, and he advanced a little, so I retreated a little more, and he went back to eating, but I felt kind of trapped on my side of the street, unable to get back to my truck.
But then a magpie landed on his back. The moose twitched him off. And again, and again, until the magpie had driven him back from the street.
Which was great, but a little unsettling since, I don't know, a bird can drive off a moose? What could he do to a mailman?