Monochrome, no barring, size of a Mockingbird. yellow bill and white throat!!
I'm Stumped!! HELP
Rex Rowan Comment and ID ( Big Thanks!! ) This one is a Yellow-billed Cuckoo. Plain brown upperparts, plain white underparts, and yellow bill. That neck-twisting posture as it looks around is pretty characteristic.
http://www.allaboutbirds.org/guide/Yellow-billed_Cuckoo/id