[Mystery birds] Field Sparrow, Spizella pusilla, photographed at Paul Rushing Park, Texas. [I will identify this bird for you tomorrow]
Image: Joseph Kennedy, 28 March 2009 [larger view].
Nikon D200, Kowa 883 telescope with tsn-pz camera eyepiece 1/500s f/8.0 at 1000.0mm iso400.
Please name at least one field mark that supports your identification.