Recovery Plan for the Northern Spotted Owl - DRAFT

differences occur in the northern and southern portions of the province. Thenorthern area is dominated by high mountains and ridges unsuitable forspotted owls and lower valleys with suitable spotted owl habitat. The resultinglandscape pattern is a mosaic of alternating valleys of suitable habitat andunsuitable ridges, a naturally fragmented environment for spotted owls. Thesouthern portion is much less dominated by mountainous areas, and spottedowl habitat is more continuous, although still highly fragmented by past timberharvest.Low Populations. The currently known spotted owl population includesapproximately 200 pair and single owl territories (WDW 1991). This numberwill change as additional areas are surveyed. Spotted owls are found throughoutthe province, although at lower densities in the northern portion and in the1-90 corridor area. The 1-90 corridor is an area of checkerboard ownershiplands (federal with state, private, or municipal) that has been harvested heavilyin the past 20 to 30 years. Approximately 20 spotted owl territories occur inthe 1-90 corridor in the western Washington Cascades province. In the northernregion, in only 22 territories are known to have produced young successfullysince 1986 (WDW 1991). In addition, owls only two territories in the 1-90corridor have produced young successfully since 1986. Reproductive successhas been higher in the southern portion of the province.Limited Habitat. Current spotted owl habitat generally is located at higherelevations, predominantly on national forest lands. Much of the accessible,low-elevation habitat has been logged previously, and current stands that haveregenerated after harvest generally are less than 80 years old.Few blocks of old-growth forest remain on state, private, and municipal lands.Most of the currently known spotted owls on these lands (outside of checkerboardownership lands) inhabit patchwork mosaics of remnant old-growthstands that survived historic forest fires within larger naturally regeneratedsecond-growth stands. The 1-90 corridor has been harvested heavily within thepast 20 years, as has the area known as the Mineral Block in the GiffordPinchot National Forest.Declining Habitat. Spotted owl habitat in the province has declined significantlyin the last 30 years. During this time the proportion of old-growth thatwas potential spotted owl habitat has decreased from about 60 percent toabout 40 percent of the area of the Mt. Baker-Snoqualmie National Forest, withsimilar decreases from about 40 percent to 30 percent for the Gifford PinchotNational Forest (Henderson 1990). The relatively low proportions of old-growthon the Gifford Pinchot National Forest resulted from the Yacolt Bum of 1902and the eruption of Mount St. Helens in 1980, as well as logging.In recent years, habitat decline has been most severe, proportion in the 1-90corridor and the Mineral Block of the Gifford Pinchot National Forest. Habitatsurrounding 38 randomly selected spotted owl management areas on the Mt.Baker-Snoqualmie and Gifford Pinchot National Forests was analyzed in 1984(Allen et al. 1989). The average proportion of suitable habitat within 1.5 and2.1 miles of the center of these areas varied between 49 and 55 percent of thetotal area at that time. Analysis of information presented in the 1991 ForestService Timber Sale Biological Assessment indicates that the average proportionof suitable habitat within 1.8 miles of spotted owl territories was near 40percent (Hays pers. comm.). The difference between these habitat estimatesduring the past 7 years is an indication of severe habitat decline in a relativelyshort period of time. In the near future, the expected net rate of habitat losswithout protective measures for the spotted owl will significantly decrease thepotential for recovery on both federal and nonfederal lands.45