Recovery Plan for the Northern Spotted Owl - DRAFT

IntroductionThis appendix presents detailed information on the individual designatedconservation areas (DCAs). Tables show the size of the areas, the currentcondition of habitat within them, the current number of known northernspotted owls, and projections of the near-term and future capability of theseareas to support owls. The tables are based on data stored in the geographicinformation system (GIS) at the Oregon State Service Center in Salem, Oregon.The map of DCAs used to produce these tables was developed by the RecoveryTeam as described in Appendix I. The map was digitized for the GIS and thenanalyzed in conjunction with ownership maps, suitable habitat maps, andmaps of owl locations.Figures are given for acres of nesting, roosting, and foraging (NRF) habitat inthe DCAs. The areas identified as NRF habitat include acres that are suitablefor some or all of the spotted owl's life needs. Information on habitat wasavailable for all national forests, all BLM districts in Oregon, and for nationalparks in Oregon and Washington. Habitat information was not available forother federal lands or nonfederal lands.NRF habitat mapping on national forests was based on regional criteria thatwere refined by local biologists on the forests. Thus, the criteria varied fromlocation to location (USDA 1988; USDA 1992). Habitat mapping on BLM landswas based on a standard set of criteria that was modified at the local levelbased on the site-specific knowledge of biologists. NRF habitat for nationalparks in Oregon and Washington was identified from an analysis of Landsatdata completed in 1991 for the Forest Service. Acres identified as suitable NRFhabitat had the following characteristics: canopy closure equal to or greaterthan 70 percent: tree species including Douglas-fir, western hemlock, andPacific silver fir; predominant tree dbh of 21 inches or greater; and developmentof a second canopy layer.Known owl locations were identified from data bases supplied by the WashingtonDepartment of Wildlife, the California Department of Fish and Game, andthe Oregon Department of Fish and Wildlife. For all three states, owl pairs andindividuals that had been verified from 1986 through 1990 were tallied.The remaining pieces of information, current projected and future projectedowl pairs, were based on calculations. The current projected" number is anestimate of the number of pairs of owls that the DCA would be expected tosupport if the population stabilized with current habitat conditions. The"future projected" number is an estimate of the number of pairs of owls thatthe DCA might support at a future time if 80 percent of the area were composedof NRF habitat. For "current projected" and "future projected," estimateswere made for federal lands and for federal and nonfederal lands combined.This does not suggest a commitment to provide habitat on those nonfederallands, but shows the habitat potential of the area if nonfederal lands were tocontribute fully to recovery.The calculations used to estimate the number of owl pairs that could besupported in a given DCA were refinements of techniques originally used byThomas et al. (1990). The refinements are described in USDA (1992). Briefly,the calculations are based on:- The proportion of a landscape that is NRF habitat,- The relationship between the size of the annual home range of an owl pairand the percentage of that home range in NRF habitat,603