Saturday, July 4, 2009

Summer is the time for youngsters!

This is the time of year to practice identifying young birds. It is not always easy. We all are familiar with the American Robin fledglings looking like the parent except with a spotted breast.

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.
This Chipping Sparrow juvenile (below), you can see it is heavily streaked but it has a dark line through its eye like the adult. In many you will see the chestnut color molting in on the top of its head. You do have to be careful that the bill color on many juveniles will be lighter than what they are when they are adults. A nestling's bill as you know is softer and fleshy yellow for feeding targets for the adults. As the nestlings develop, the bill hardens and darkens in coloration as in this Chipping Sparrow. As you see on this juvenile Tufted Titmouse it has some yellow gape showing at the posterior section of its bill. To end the week I will share this nice looking Blue-winged Warbler captured during the Oak Openings MAPS project. It is not as handsome as he was in spring. A month of territorial chasing and nesting responsibilities has his feathers worn. He is ready for a new set of feathers as soon as the breeding season is over!

Enjoy the birds of summer!

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