Here is his story unedited:
I woke up last week to the sound of a vocal bird outside my window. Most of the time, even while half-asleep, I'm continually monitoring the common bird sounds I hear, but this call got me out of bed because it was a loud scream and because I had no idea what it could be. This immature Cooper's Hawk sat outside long enough for me to snap a few pictures through the bathroom window. I think this one turned out the best. I was thankful to get the opportunity to take a long and studied look at the bird. It's a resident of the neighborhood that I've glimpsed several times over the past couple of months. It flew through the yard again today, presumably gunning for a chickadee or titmouse or mourning dove.
I'm impressed he was able to get the hawk. I saw one in my parents' back yard a few weeks ago, also preying on the birds at the bird feeder. He had a reddish chest, which was the most notable characteristic about him. Overall he was very dark. I spotted him from within the house and by the time I ran out the front door to get my camera from the car he had already flown away. I'm suspecting it was probably a Cooper's Hawk as well, although the majority of the pictures I'm finding show a lighter-colored chest, as in Chris' picture above. I think there's a possibility it could have been a Sharp-shinned Hawk, but I have no way of truly knowing since I only saw it for a moment. According to my Sibley Guide, they also tend to hunt small birds at feeders and their average height is 11" versus Cooper's Hawks at 16.5." Also considering where I saw him in the tree I think it's more likely it was a smaller bird since I think it would have been difficult for him to land within this tree if he were a larger bird (the difference between a 36" wingspan and a 42" one). Again, I can't be sure until I spot another one, but it's interesting to learn about them!
Other winter sightings I've had here outside Boston have been flocks of Bufflehead ducks on the Charles River every morning during my drive to work. I also see swans every morning, and today there was a pair curled up and sleeping on the ice. I realize they're nice and insulated but it makes me shiver just looking at them.