Contopus cooperi. Some birds aren't as fancy as others, but I like 'em anyway. :) This particular photo has significance for me because I actually got to "know" this bird a little. He liked sitting on top of that one-stick snag, about 10 feet off the ground, where he could see all around himself easily. I saw him there on more than one occasion. Found in Sweetwater Wetlands, southern Arizona, USA. I am also happy with this photograph because I took it with a 1300mm lens, hand-held. The habit of sitting in a conspicuous treetop perch is typical of these birds, and they feed off large insects. In this case, I'm sure he found the abundant dragonflies very tasty. Some people say that this bird's song sounds like he's saying, "Quick, three beers." I find descriptions like this helpful to learn to recognize bird songs, and when I hear a song, then I know what to look for.