An avian mini-drama unfolded before my mic one January day when a Red-tailed Hawk stooped from high up onto an American Kestrel. The Kestrel noticed the hawk just moments before he became a puff of feathers and escaped. He turned around and pursued the much larger hawk, harassing him mercilessly until he landed on top of a Saguaro cactus to wait out his punishment. The Kestrel dived and harassed for several minutes, finally leaving the Red-tail to lick his wounded pride. In this sample, the Kestrel is diving repeatedly and the Hawk responds with a scream, then a series of "barks" that I had not previously heard.

Douglas Von Gausig (recordist, copyright holder), Naturesongs.com