Recovery Plan for the Northern Spotted Owl - DRAFT

Fishestheir dispersal capabilities are limited; and there is considerable geneticvariability within species. The clouded and Oregon slender salamanders areassociated closely with coarse woody debris. Populations of this group have notbeen surveyed sufficiently to assess the status of many of the species' populations.Their special natural history traits include low mobility and dependencyon moist environments for at least part of their life cycles. They have beenincluded as priorities among a group of riparian associates because informationis limited on the status of their populations. In addition, there is evidence of adecline in amphibians around the world, including the Pacific Northwest(Blaustein and Wake 1990). The cause of this decline is not known, but includesloss of habitat. Bury (1983) and Corn and Bury (1989) assessed theeffects of logging on the tailed frog, Oregon slender salamander, and the Pacificgiant salamander. Gomez (1992) found the tailed frog and Pacific giant salamanderin greatest numbers in riparian areas of mature and old-growth forestsin comparison to deciduous forest, pole-sized stands, and early clear-cuts.In addition to the riparian associates that are identified in Table D.3, thecommittee designated the Oregon slender, Larch Mountain, Siskiyou Mountain,Del Norte Pacific giant, Cope's giant, and Olympic salamanders (fourspecies), and tailed frog as priority species. Selection of these species wasbased on their extremely restricted geographic range, association with olderforests, or status as candidates for federal listing. Because of their restrictedranges (Figures D.3 - D.5), there was a need for some protection through minoralterations in the location of designated conservation areas.The list of fishes for consideration in the recovery plan includes 28 species inwestern Washington and Oregon and northwestern California (Table D.4). Onestock, the Sacramento River winter chinook salmon, is listed federally asthreatened, and the rest of the species are designated as "species of specialconcern" by the states in which they occur. Of particular concern is the largelist of streams with stocks at risk and the number of these stocks that isconsidered at risk in Oregon, Washington, and California (Nehlsen et al. 1991,Williams et al. 1989, Moyle et al. 1989), including 85 streams and 178 fishstocks in California, 177 streams and 386 stocks in Oregon, and 86 streamsand 202 stocks in Washington.Molluscs'Fifty-eight species of rare and endemic molluscs occur within the range of thenorthern spotted owl: nine are candidates for federal listing, and 29 are "speciesof special concern" (Table D.5). Of these 58 species, the Karok land snailis a category 1 candidate for federal listing and 10 other species are rated ascategory 2 candidates (see Table D.5 for definition of categories). The 58species include 23 aquatic and 35 land forms, and only one occurs in all threestates. Many of the species are endemic to only one state (Frest and Johannes1991). Dispersal capability of this group of invertebrates is low, particularly forthe terrestrial species. At least 43 species are considered to be old-growthassociates (T. Frest pers. comm.); 45 are riparian associates.A number of the land and freshwater molluscs (bivalve and snail) in the westcoast states have limited geographic ranges. Most of these species are confinedto a coastal belt that extends only from the crest of the Cascades to thePacific. Within the owl's range, there are three distinct land snail provinces.The Oregon province extends from coastal lritish Columbia just into extremenorthern California; the Washington province extends east from the Cascadescrest: and the California province is coastal from northern California.Largely extracted from inforniatiori supplied by Terrence Frest of Deixis consultatants (letter of 17 September 1991).348