This looks like an (Eastern) Winter Wren Troglodytes [troglodytes] hiemalis at Cottonwood Campground, BBNP, Brewster county, Texas on December 12, 2010:
This bird from Choke Canyon State Park, Duval county, Texas on January 26, 2009 looks closer to the "eastern" subspecies of Pacific Wren, Troglodytes pacificus salebrosus...:
