On 27 October 2009, 25 km east of Chugwater, Platte County, Wyoming, I spotted a male Northern Harrier (Circus cyaneus) approximately 900 m away hunting at a height of 1–2 m over a pasture. As it flew, the harrier frequently flushed passerine birds, which it did not pursue. After approximately 30 seconds, the harrier suddenly turned 180° and flew east at a faster rate of speed. I then noticed a Merlin (Falco columbarius) that had come in from the west and was now close to the harrier. The Merlin began following approximately 5–10 m behind the harrier and using it as a beater, chasing the passerines being flushed by the larger raptor, which had resumed its slower hunting speed.