[Mystery bird] Field Sparrow, Spizella pusilla, photographed on the Katy Prairie, Katy, Texas. [I will identify this bird for you in 48 hours]
Image: Joseph Kennedy, 6 February 2010 [larger view].
Nikon D200, Kowa 883 telescope with TSN-PZ camera eyepiece 1/350s f/8.0 at 1000.0mm iso400.
Please name at least one field mark that supports your identification.