In Vancouver, the crows all go east at night to a roost in nearby Burnaby; at it's height, they'res 2000 crows flying over east van, probably more...it's quite a sight that kinda freaks people out the first time they see it...there is a Raven family in my 'hood which is very cool, as Ravens don't usually hang out in Vancouver itself...
I dig crows and Ravens too, especially Ravens as they are both really smart; crows can be really ruthless though...there's probably video of the crow flight out there...Tony