I've been seeing a lot of hawks in the neighborhood, lately. Mostly red tails. I saw one today perched on the Harvard gates across from the foot bridge. I saw one atop the "May I take your order?" kiosk at a Burger King drive-thru near Fresh Pond a few years ago—fearless! Later today, I'm going to try to take a picture of one that roosts near the BU bridge.
I don't know enough about hawks, but I am looking forward to spending more time with this interesting resource from the Hawk Migration Association of North America. A nifty slide-show guide to identifying hawks in flight.