Aerial Talon-Grappling in Northern Harriers

Aerial talon-grappling (Ellis, Wildl. Monogr. 70, 1979) between cospecifics has been described for some falconiforms (Brown and Amadon, Eagles, hawks, and falcons of the world, McGraw-Hill, New York, 1968; Ellis 1979; Newton, population ecology of raptors, Buteo Books, Vermillion, SD, 1979). These researchers reported that the birds locked on or both feet and somersaulted together, releasing their grip while still in the air. In some Haliaeetus eagles, kites (Haliastur and Milvus) and Upland Buzzars(Buteo hemilasius) talon-grappling is thought to function in courtship between mated birds (Brown and Amadon 1968). Newton (1979) believed that in some kestrels (Falco), Peregrine Falcons (F. peregrinus) and Golden Eagles (Aquila chrysaetos), talon-grappling is an agonistic behavior related to terrirorial defense.