[Mystery bird] Grasshopper Sparrow, Ammodramus savannarum, photographed in Attwater Prairie Chicken Refuge, Texas. [I will identify this bird for you tomorrow]
Image: Joseph Kennedy, 6 December 2008 [larger view].
Nikon D200, Kowa 883 telescope TSN-PZ camera eyepiece 1/90s f/8.0 at 1000.0mm iso400.
Please name at least one field mark that supports your identification.
Review all mystery birds to date.