AVIS-IBIS

Birds of Indian Subcontinent

Nesting Populations of Red-Tailed Hawks and Horned Owls in Central New York State

Publication Type:Journal Article
Year of Publication:1957
Authors:Hagar, Jr., DC
Journal:The Wilson Bulletin
Volume:69
Issue:3
Date Published:1957
ISBN Number:00435643
Keywords:Accipitridae, Buteo, Buteo jamaicensis
Abstract:Observations on hawks and owls were made on a 52-square-mile area in southeastern Madison County, New York, from the fall of 1948 through the spring of 1952, with the exception of summers. The common, large raptors were Red-tailed Hawks and Horned Owls, and my attention was given to them, nearly to the exclusion of other species. Both species showed a strong tendency to use their respective woodlots in successive years. The owls appeared to be dependent upon the hawks for providing nests. The owls seemed restricted to larger woodlots with scattered hemlock to a greater extent than were the hawks. Beech was the preferred nest tree of the owls, whereas beech and sugar maple were equally important for the hawks. An estimated 11 pairs of Horned Owls and 23 pairs of Red-tailed Hawks on the area in the spring of 1952 gave breeding population densities of one pair per 4.4 square miles and one pair per 2.2 square miles, respectively. The combined population would have allowed 1.4 square miles per pair. Individual pairs of hawks and owls often occupied overlapping territories but attempts to use closely adjacent nest sites usually resulted in abandonment by the hawks. The hawks fledged 1.9 young per pair, and the owls, 1.7, on an average. The average brood sizes in 1952 were about half those in 1951 for both species. Nearly 40 per cent of the freshly constructed Red-tailed Hawk nests found in early spring had no young, probably because eggs were never laid in them.
URL:http://www.jstor.org/stable/4158602
Short Title:The Wilson Bulletin
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