Recovery Plan for the Northern Spotted Owl - DRAFT

Province Isolation. The eastern Washington Cascades province is isolatedsomewhat from other spotted owl subpopulations on northern, southern, andwestern boundaries. The two provinces that comprise the Washington Cascadesare connected by contiguous habitat and owls in only a few areas. Thenorthern portion of the province is virtually at the edge of the species' currentrange and the few spotted owls within this region are isolated from largergroups of owls south of Lake Chelan. Spotted owls in southern British Columbiaare found in low numbers and densities, and are unlikely to providedemographic support to owls in northern Washington. The degree of provinceisolation in the Columbia River area is unknown.Vulnerability to Natural Disturbances. There is a significant potential forlarge-scale fire in the eastern Washington Cascades province. There is a lowprobability that any conservation area created in the eastern Cascades ofWashington will avoid stand-replacing wildfire over a significant portion of thelandscape during the next century (Appendix F). As spotted owls in theprovince currently are clustered in a few key areas, fire poses a severe naturalthreat to population recovery. Similar to the situation in the western Cascades,volcanic eruptions of Mt. Adams, Mt. Rainier, or Glacier Peak couldeliminate one or more conservation areas and increase within-province isolationof subpopulations.5. Threats by Province within OregonOregon Coast RangeThe Oregon Coast Range province lies west of the Willamette Valley andextends along the coast from the Columbia River south to about the CoquilleRiver. The province is characterized by generally low-elevation, productiveforests in areas of high precipitation. Land ownership of the approximately4.48 million acres in the Coast Range is 57 percent private, 13 percent ForestService, 17 percent BLM, and 13 percent state (Figure 2.4a). Federal lands arerepresented by the Siuslaw National Forest and parts of the Salem, Eugene,Coos Bay, and Roseburg BLM Districts. Timber harvest and extensive wildfireshave greatly reduced and fragmented spotted owl habitat. Threats to the owlpopulation in this province are greater than those in any other Oregon province(Table 2.4).Low Populations. The owl population within this province is extremely low,particularly in the northern three-fourths of the province. A total of about 325pairs has been found within the last 5 years. Owls are poorly distributedwithin the province and exist at very low densities with many pairs isolated bymore than 10 miles. Forty-five percent of the known spotted owl sites lie southof Highway 38, in the southern quarter of the province. Most spotted owl siteswithin the province have less than 40 percent suitable habitat within homerange areas (USDI 1991a).Most owl sites are located in the southern portion of the province and areassociated with BLM lands. As a result of timber harvest on the interspersedBLM and private lands, the forest landscape is very fragmented.The Elliott State Forest is a 93,000-acre block of state-owned land northeast ofCoos Bay. Surveys in the Elliott State Forest in 1991 revealed 20 pairs and 18single owls. These owls are of particular interest due to the age structure oftrees within the forest. Sixty percent of the Elliott State Forest is composed oftrees from 90 to more than 140 years of age (trees on the remaining area are48