Before we talk, you need to watch the video above. It's just one minute and 24 seconds. You'll observe a crow (probably a 'hooded crow') pick up the lid to a jar, set it down on the apex of a snow-mottled roof and slide down one side, carefully keeping its feet on the lid until it gets to the bottom. Then it picks up the lid, flies back to the apex, tests out another face of the roof, finds it lacking, returns to the original position, and slides down again.
It is a remarkable demonstration of the intelligence of the crow, which sits on a smart branch in the animal tree within the family Corvidae. There is something so deliberate about this play: the crow uses a toy; it searches for the best sledding path; it repeats the adventure down the roof; it keeps upright with its feet planted on the lid when, as a bird, it could simply fly. The bird does not want to travel down the roof, it wants to slide down the roof.
I wanted to know if there was a greater significance to this video and this amazing bird. So, I called up Alan Kamil, who has been studying corvids for decades and is co-director of the Center for Avian Intelligence at the University of Nebraska. I've got to send you this YouTube clip of this crow sledding down a roof in Russia, I told him.