Proximity Nesting: The Great Horned Owl and Red-tailed Hawk

Introduction: Forty-two nests of the Great Horned Owl (Bubo virginianus) and 78 nests of the Red-tailed Hawk (Buteo jamaieensis) were surveyed during a three-year ecological study (1982–84). In 11 instances nests of the two species overlapped the hunting areas of the other. Home ranges, in which most hunting takes place, have been defined by various authors (Miller, 1930; Baumgartner, 1939; Hagar, 1967). For this study Hawks and Owls nesting within one-half mile of each other were compared. The proximity nesting of these two species seemed likely to increase the possibility of predation upon the young of the other, as has been previously suggested (Craighead and Craighead, 1956; Fitch, 1940; Orians and Kuhlman, 1956; Seidensticker and Reynolds, 1971; Mclnvaille and Keith, 1974)