Characteristics of spotted owl habitat in landscapes disturbed by timber harvest in northwestern California

We studied Northern Spotted Owl (Strix occidentalis caurina) habitat characteristics within two landscapes in northwestern California. One landscape was dominated by extensive areas of previously harvested Douglas-fir (Pseudotsuga menziesii) forest that contained small, isolated patches of mature and old-growth forest. The other landscape was dominated by larger, less isolated patches of mature and old-growth Douglas-fir forest interspersed with previously harvested forest. Spotted Owls in the more extensively logged landscape used sites that had more complex forest structure than available sites. They also used areas that had more mature and old-growth forest than areas not occupied by owls. In the less disturbed landscape, Spotted Owls used areas that had more mature and old-growth forest than sites occupied by owls in the more disturbed landscape. Our results provide further evidence that Spotted Owls select nest and roost sites with more complex forest structure and with greater amounts of mature and old-growth coniferous forest than is generally available to them.