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Holthausen, Richard S.; Raphael, Martin G.; McKelvey, Kevin S.; Forsman, Eric D.; Starkey, Edward E.; Seaman, D. Erran. 1995. The contribution of Federal and non-Federal habitat to persistence of the northern spotted owl on the Olympic Peninsula, Washington: report of the Reanalysis Team. Gen. Tech. Rep. PNW-GTR-352. Portland, OR: U.S. Department of Agriculture, Forest , Service, Pacific Northwest Research Station. 68 p. We analyzed likely patterns of distribution and persistence of northern spotted owls (Strix occidentalis caurina) on the Olympic Peninsula. Analysis focused on the effects of Federal habitat under provisions of the Northwest Forest Plan; additional benefits to the owl population of different levels of habitat retention on non-Federal lands; effects of establishing a habitat connection between the Olympic Peninsula and other parts of the owl's range; the likely rate of habitat regrowth in the National Forest and its effect on the owl population; and the likely effect of a worst-case fire. We used a spatially explicit population model for northern spotted owls for the analysis and also reviewed current information on demographics and likely owl population numbers on the Olympic Peninsula. We concluded that it is likely, but not assured, that a stable population of northern spotted owls would be maintained in portions of the Olympic National Forest and the Olympic National Park in the absence of any non-Federal contribution of habitat, and that the retention of non-Federal habitat would make a biologically significant contribution to the maintenance of the population. Finally, we concluded that a habitat connection across southwestern Washington, based on the design proposed by the Northern Spotted Owl Recovery Team, would have little effect on the status of the owl population on the peninsula if that population was stable or nearly stable.