Northern spotted owl habitat and populations: Status and threats

The northern spotted owl (Strix occidentalis caurina) was listed as threatened under the Endangered Species Act in 1990 (USFWS 1990). Providing adequate amounts of suitable forest cover to sustain the subspecies was a major component of the first recovery plan for northern spotted owls (USFWS 1992) and a driver in the basic reserve design and old-forest restoration under the Northwest Forest Plan (NWFP, or Plan) (USDA and USDI 1994). The reserve design included large contiguous blocks of late-successional forest, which was expected to be sufficient to provide habitat for many interacting pairs of northern spotted owls. As such, the selection of reserves generally favored areas with the highest quality old-growth
forests, but some areas of younger forest were also included with the expectation that they would eventually develop suitable forest structure characteristics and contribute to spatial patterns that would sustain spotted owl populations.