Northern Harrier feeding

I took a walk this afternoon through a swamp in my neighborhood, gathering downed branches to make into tree blocks. It was a welcome diversion from the insanity that has consumed Boston since Monday’s bombings at the marathon. There is so much to say about that, but not in this post.

There is a footpath that goes around the perimeter of this small swamp, and it’s a great place to bird watch. The swamp is always filled with the chatter of song birds and the tapping of woodpeckers. I saw what I thought was a big squirrel on a log about twenty five feet from the trail, but what turned out to be a bird of prey that had just caught a bird. I sat down to watch it, wishing I’d brought a camera with me rather than the folding saw I had in my back pocket. The camera on phone is no good for photos at that range, and I wasn’t sure what kind of bird it was and wanted to be able to identify it once I got home, so I sketched what I saw on a piece of scrap paper. Red-tailed hawks and their close relatives, red-shouldered hawks, rough-legged hawks, and broad-winged hawks, all members of a group classified as buteos, are the most common birds of prey around here. We also see turkey buzzards and Cooper’s hawks pretty regularly. This bird was distinctly falcon like, and I knew it wasn’t a peregrine (although that wouldn’t have been out of the question, they do nest in Boston). Looking at one of my field guides, it was easy to identify it as a male Northern Harrier. They summer in this area and may stay through the winter in some cases.
Northern Harrier identification

I watched it for about twenty minutes from my spot on the trail. He was mostly unconcerned with my presence, other than stopping to watch me once in a while. I didn’t get to see him catch his prey, but it must have just happened. He was perched on a big fallen log, steadily removing feathers with his beak while holding the bird down with one of his long legs. Downy feathers scattered in the wind. It’s always exciting for me when I get to watch a bird of prey eating its kill, and this bird was especially handsome. His legs were long and slender, his body sleek with dark grey head and wings, and cream and reddish belly. His tail was long and narrow, mostly white with dark bands. After a few minutes he started tearing long strips of flesh and eating them. I watched for about fifteen minutes before he flew off to a higher branch, taking what remained of the bird with him.
This is the spot on the log where he was perched. You can see just a few drops of blood, but also a clear sac with a thick yellow fluid coming out of it. I haven’t ever seen anything like this and I am not sure whether it is an internal organ from the prey bird, or something that was already on the log. Any ideas?

On the ground right below the log was the beak of the prey bird, long and yellow with tufts of small black feathers still attached. Judging by this and the other feathers, it was probably a robin.