Elicited Territorial Responses of Northern Bald Eagles Near Active Nests

• Published in: The Journal of wildlife management 1987-07, Vol.51 (3), p.551-554
• Main Authors: Mahaffy, Mary S., Frenzel, L. Daniel
• Format: Article
• Language: English
• Subjects: Animal ethology; Animal nesting; Aves; Biological and medical sciences; Bird nesting; Birds of prey; Eagles; Forest management; Fundamental and applied biological sciences. Psychology; Haliaeetus leucocephalus alascanus; Incubation; National forests; Nesting sites; Psychology. Psychoanalysis. Psychiatry; Territorial invasion; Territories; Vertebrata
• ISSN: 0022-541X; 1937-2817
• DOI: 10.2307/3801267

Territorial behavior of nesting northern bald eagles (Haliaeetus leucocephalus alascanus) to eagle decoys was studied on the Chippewa National Forest in northcentral Minnesota in 1979 and 1980. Mounted, live, and papier-mâché adult bald eagle decoys were used to elicit responses near 16 active bald eagle nests. Similar reactions of circling and calling by both sexes were elicited by all decoy types. Response distances from nests averaged 0.56 ± 0.18 (N = 4), 0.55 ± 0.17 (N = 4), and 0.72 ± 0.21 km (N = 2) for incubation, early brooding, and late brooding, respectively. There was no significant difference (P > 0.1) between periods. The average response distance was 0.59 ± 0.26 km for all periods. Territory boundaries appeared relatively stable from year to year. Eagles responded to decoys at a greater distance (0.67 ± 0.18 km, N = 7) when water was between the decoy and the nest than when land intervened (0.40 ± 0.03 km, N = 3) (P < 0.01).