Have you ever been challenged by sparrow juveniles? I have and it takes some experience and some thinking to get them down. I must say about ten years ago I was really spoofed by a juvenile sparrow we had captured during the Navarre MAPS session one summer. I wanted to call it a Lincoln’s Sparrow with the nice markings on its breast as the Lincoln’s Sparrow has. Well, it turned out to be a juvenile Swamp Sparrow. I sent pictures to the Carnegie Museum and they said “Sorry but this is a Swamp Sparrow juvenile.” So young sparrows are not easy no matter how you look at them. I will call it GIZ which has been used for hawk identification but I believe it applies here when looking at some of the common sparrows if not most of the eastern sparrows. Their general impressions (GIZ) tell you who they are. Take a look at these sparrows. I have paired them up with an adult so this should be helpful. See the bill is turning pink and on most juveniles you will see the white eye ring as you see in the adult Field Sparrow. Their back coloration is similar to the adult. It is the breast of the juvenile sparrows that causes frustration.
Enjoy the birds of summer!