I've had this happen a lot by gulls. Every spring they nest at various rooftops, and anyone walking within 50 yards of the house gets swooped repeatedly.

It's definitely my least favorite bird.

The strangest part of this to me is that I've never once had this happen in the Willingdon Park office park near Brentwood in Burnaby. It is absolutely covered with crows overnight, at all times of the year.[1]

But the one time I walked down the wrong sidewalk in Point Grey (so Vancouver 'proper') during springtime, the back of my head gets smacked.

[1] Perhaps the Burnaby/Willingdon crows consider the absurd amounts of crow shit on cars, sidewalks, buildings, etc. to be adequate warning? The stench after a rain is... eugh.

The eagles are somewhat less maneuverable- crows are very nimble flyers. I just saw a crow on my walk today land backwards in the wind. They can avoid the claws and beak... Sort of like a monkey harassing a tiger. They'll actually pull feathers off the eagle. Every now and then the eagles pull some crazy moves though to get away, they'll tilt sideways and fall. It's like a move you might see in fighter jet dogfights.

Around here harriers also get harassed by the crows.