Forest Structure Within Barred Owl (Strix varia) Home Ranges in the Eastern Cascade Range, Washington

Abstract Competitive interactions with Barred Owls (Strix varia) are an important factor contributing to the decline of the Northern Spotted Owl (Strix occidentalis caurina) population. Understanding the degree of similarity in fine-scale habitat associations for Spotted Owls and Barred Owls will help land managers evaluate whether there are specific vegetation conditions that could favor Spotted Owls over Barred Owls. From March 2004 to September 2006, I tracked 14 radio-tagged Barred Owls in the Okanogan-Wenatchee National Forest in the eastern Cascade Range, Washington. I analyzed forest structure characteristics from 170 plots sampled within areas used by the radio-tagged owls. I identified three forest types present within the Barred Owl home ranges, including: (1) open ponderosa pine (Pinus ponderosa), (2) simple-structure Douglas-fir (Pseudotsuga menziesii), and (3) complex-structure grand fir (Abies grandis). I compared individual forest structure characteristics and the three forest types to the ...