White-breasted Nuthatch at nest, wing flaring 

Female White-breasted Nuthatch was at her nest site in a snag at Swauk Prairie. While waiting for the male to appear, and after, she flared her wings repeatedly, but when the male did show, he made a hand-off of some nesting material that the female promptly dropped into the cavity. Prior to the beginning of this video, a chipmunk had come to the snag to investigate; the wing-flaring may have been an aggressive posture to ensure the chipmunk didn't invade the nest cavity.