Yesterday, we went to Soundview Park to observe birds, and we saw a lot of robins, phoebes, black sparrows, and tree swallows. We were observing the boxes we made to see if any swallows were inside. At first there wasn't, but for some reason I had a lot of good luck.
Yesterday I saw a blue tree swallow with my own two eyes. I spotted it fighting with a black sparrow that was on top of his house basically telling it to "Get off my house!" Then it went inside of the next box.