Posted by Mark Brown (204.48.169.252) on May 29, 2002 at 23:12:56:
The first time I saw this photo I thought: "this bird has not flown yet", but I could not articulate why. Ms. Nelson has ably done so. Next Ms. Nelson mentions how short the tail seems. One way to tell the difference between a juvenile Verdin and a juvenile Bushtit(its closest North American relative) apart is the juvy Verdins shorter tail. Next she mentioned the birds feet as looking like a vireo or oriole. The Verdins hold branches like a chickadee, even feeding upside down. This bird is grasping the branch more like a chickadee than a sparrow. Since we agree this is a very young bird it must be near its nest. By looking at the leaves in the photo I have determined that this bird is in a Mesquite tree. We know that this bird is in Arizona and specifically Suguaro National Park. That is Sonoran Desert habitat. Mesquites are in this habitat and Verdin nest in thorny shrubs and trees like the Mesquite using the thorns to make their nests. Black-chinned Sparrows nest in open chapparral on arid hilly slopes. Gray-headed Juncos nesting habitat consists of arid coniferous woodland, like Pinyon Pines, White Firs and Bristlcone Pines. (Per Dunn & Garrett Birds of S. Cal) The San Diego Breeding Bird Atlas website states about breeding Verdin in Anza Barrego(sort of like Arizona): "Eggs 21 March -23 April. Watch for fledglings (grayhead) April-June." Bent says it takes ten days for the Verdin eggs to hatch and 21 days until the birds fly. We know this picture is dated May 28 so it is a fledgling. The ID guide to N. A. Passerines has a nice sketch of the bill and headshape of juvenile Verdin and they look like this bird. Dunn & Garrett's Warbler book talks about juvenile Verdin because people confuse them with Lucy's Warblers. The picture there (pg. 55) shows the odd eye shape like this bird reminescent almost of a redpoll. I still believe this to be a juvenile Verdin.