Recovery Plan for the Northern Spotted Owl - DRAFT

continued-StatusabState Considered Priority RiparianSpecies Fed WA OR CA at Rlskc Species AssociateSockeye salmon X X XOncorhynchus nerkaSummer chinook salmon X X XOncorhynchus tshawytschaSummer steelhead trout SC X X XOncorhynchus mykissTidewater goby C2 SC X XEucylogobius newberryiTomales roach SC XLavinia symmetricus subsp.Umpqua chub SR XOregonichthys kalawatsetiOregon chub PrE SR XOregonichthys crameriWinter steelhead trout X X XOncorhynchus mykissWA = Washington OR = Oregon CA = CaliforniaaFederal status: E = endangered, T = threatened, C = candidate, C2 = category 2 candidate, U.S. Fish and Wildlife Service candidatesthat need additional information to propose as threatened or endangered under the Endangered Species Act. PrE = proposed endangered.Pet = petition pending.bState status: WA: C = candidate, M = monitor, X = extirpated, G = game; OR: SC = sensitive (critical), SV = sensitive (vulnerable),SR = sensitive (rare), SU = sensitive (undetermined), X = extirpated; CA: SCT = state candidate for listing as threatened, SC = species ofconcern, E = endangered Sources (states): California Department of Fish and Game (1991a). Oregon Department of Fish and Wildlife(1991), Washington Department of Wildlife (1991a and 1991 b).CSee Moyle et al. (1989), Nehlsen et al. (1991), Williams et al. (1989).There are sizable endemic species clusters in the land snail genera Monadenta,7Tllobopsts, Megomphix, Haplotrema, Vespericola, and Hemphillto Physicalfactors limiting their distribution include geologic history, substrate (some arerestricted to limestone, e.g., the candidate Monadenia troglodytes, endemic tothe Siskiyou Mountains and the area around Mt. Shasta), moisture requirements,and cover. In general, land snails in this region require relativelyundisturbed cover. Most thrive in lowland forests and the areas aroundsprings. Many species seem to be associated specifically with lowland oldgrowthforests, and most are extremely limited in distribution. The malonejumping slug, HemphillMa malonei occurs only on the slopes of Mt. Hood. Thegenus Megomphix is known only from sites in the Puget Sound region and inthe Willapa Hills, of southwest Washington. In recent years, only one site hasbeen found to support Megomphix hemphilli.The delineation of freshwater mollusc provinces is similar to that of land snails.The Pacific drainage is situated similarly to the coastal land snail provinces.The Columbia drainage is a separate unit; and the Interior drainage provinceintersects the owl range in northern California. Endemic clusters are notedmost in the family Hydrobiidae and in the genus Juga. The family Lancidae ismostly coastal and occurs mainly in a few streams in southwest Oregon andnorthwest California. Species confined to single streams or springs are notuncommon. Many small and some large taxa are restricted to particularstreams in the area such as, the Rogue and Umpqua systems in Oregon; theKlamath and upper Sacramento in California; the lower Columbia and ColumbiaGorge in Washington and Oregon; or to one or a few coastal streams.Generally, molluscs are affected by any increase in siltation, decrease in flow,nutrient enrichment, and damming or other flow impediments. The rare andendemic forms are particularly affected.352