I went for a quick hike after work and I saw a bird I'd never seen before.
We were in the Blue Hills Reservation, coming down off of a hill and we saw a Scarlet Tanager high up in a tree. It's a very cool bird and has a really familiar song. Apparently there are some in the Arnold Arboretum, but since they stay so high up surface dwellers never get a chance to see them. Here's an example I found in user badjoby's flickr: