I'd mentioned the mysterious behavior of our crows to Sara Zarr in response to her Facebook link to the NPR story on crows. (Read it. Interesting!)
Our crows flock to the roof top at Levi's Plaza and perch on the railings for "meetings" in the afternoon. In small groups, they practice walking around like humans while the crows on the railings critique their technique and progress. After a certain period of time, the meeting is adjourned and they fly off in all directions, just as they'd arrived.
Spooky, I tell you! Who knows what sorts of mischief they're plotting in the late afternoon when they think no one is watching.