Birdwatching in the City

I saw a hawk, or someother such raptor, yesterday. I was standing on top of the Fuji Grand and looking out towards the city, when I spotted what looked like hawk, nigh 10 meters away. He was flying in large slow circles, each one overlapping the last slightly, so he covered some new ground with each circle. A beautiful bird, dark brown on top, a dusty red brown underneath and long finger-like feathers on his wingtips; big too, a wingspan of probably 60cm or more. I watched him for probably five or six minutes before he got too small to see. I can't imagine what he was hunting, there are really no green or even spaces near the Fuji (that I'm aware of), perhaps though, there are enough pigeons, sparrows, and rats to keep him feed. I couldn't help but think about all of the tiny dogs I see around though.