Nest-Site Selection by Eastern Screech-Owls in Central Kentucky

• Published in: The Condor (Los Angeles, Calif.) Calif.), 1990-11, Vol.92 (4), p.982-990
• Main Authors: Belthoff, James R., Ritchison, Gary
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal nesting; Animal, plant and microbial ecology; Animals; Autoecology; Aves; Biological and medical sciences; Bird nesting; Bird songs; Birds of prey; Forest habitats; Fundamental and applied biological sciences. Psychology; Nesting sites; Otus asio; Owls; Statistical variance; Tree cavities; Vegetation; Vertebrata
• ISSN: 0010-5422; 1938-5129
• DOI: 10.2307/1368734

From 1985-1987 we located 15 Eastern Screech-Owl (Otus asio) nests in central Kentucky. By comparing used nest sites to randomly chosen unused nest sites, we determined which features of the nest tree/cavity and surrounding vegetation influenced nest-site selection. We employed multivariate statistical techniques and assumed that features contributed to choice if their means differed significantly in the two samples, or if the used sample exhibited significantly reduced variance. Eastern Screech-Owls selected nest sites based on the depth of the cavity and, to a lesser degree, cavity height and entrance size. Neither tree species nor entrance orientation (direction) of the cavity hole were important in nest selection. Similarly, nest-site vegetation parameters appeared to play little role in nest-site selection. If suitable cavities are limited in supply, and cavities with nonoptimal characteristics reduce protection from predators and decrease reproductive success, then the availability of suitable cavities may limit Eastern Screech-Owl populations.