Yesterday we had a Blue-headed Vireo in our yard singing, the first we have seen this spring. I was first alerted to it by it's song, then I could see it high in the maple tree. It was backlit by the sun at first, so I studied it's shape. This is a big-headed, broad-necked bird with a relatively short tail, and a rather thick bill that is slightly hooked, as seen on the last photo. Look how short and small, compared to the size of the bird, the tail looks on the last photo. I thought about how these shape clues said vireo to me and helped me immediately know it from other birds, such as warblers.
Shape matters and can be an enormous help in bird identification. In our new Stokes Field Guide To Birds Of North America, coming out this fall, we will have a new way of incorporating shape into your birding.
I so enjoyed watching this one lone vireo, an early migrant, pausing for a moment in our yard, then making its way northward to its breeding grounds, wherever that may be. Safe journey.