Characteristics of Barred Owl (<em>Strix varia</em>) nest sites in Manitoba, Canada

Abstract

Whiklo, Todd M., and James R. duncan. 2014. Characteristics of Barred Owl (Strix varia) nest sites in Manitoba, Canada.Canadian Field-Naturalist 128(1): 38-43.during 2009 and 2010, nine Barred Owl (Strix varia) nest sites were located in Manitoba, Canada, and data on nest trees, nest structure, and nest site habitat were collected. Nests were located in a variety of tree species, including Balsam Poplar (Populus balsamifera), Paper Birch (Betula papyrifera), Trembling aspen (Populus tremuloides) and Burr Oak (Quercus macrocarpa). all nests were in tree cavities, and the majority of nests were in dead trees (67%) and had lateral openings (67%). habitat surrounding nest trees and estimated canopy cover were highly variable. diameter at breast height of nest trees, cavity width, and cavity depth were consistent and were determined to be the most reliable indicators of nest suitability for breeding Barred Owls. We conclude that the distribution of nesting Barred Owls is influenced more by availability of suitable nest sites than by nest tree species or nest site habitat.

Adult female Barred Owl (Strix varia) eating small caterpillars (family Geometridae) while guarding a recently fledged chick in Winnipeg, Manitoba

“…identified from exoskeleton remains recovered from the stomachs of Barred Owl specimens or from nest substrate and regurgitated pellet materials. 4,5 This account is the first record of Barred Owls actively stalking and eating small moth caterpillars. It is noteworthy because the remains of soft-bodied boneless prey items are either difficult to locate or absent from Barred Owl prey remains obtained from regurgitated Photo credit: Aaron Janzen.…”