Recovery Plan for the Northern Spotted Owl - DRAFT

southwestern British Columbia. Good's (1989) D. ensatus is found in the SanFrancisco Bay area, his D. tenebrosus from lower Sonoma County, California,through southwestern British Columbia, and Nussbaum's (1970) D. copei inthe Columbia River Gorge (both Oregon and Washington sides), the OlympicPeninsula, the Willapa Hills, and the southeastern Washington Cascades(Figure D.5).Adults are common in many areas, but they are nocturnal and secretive. Theycan be found in moist coniferous forests under bark, logs, rocks, and wanderingabout on the forest floor (Beatty et al. 1991). During the breeding seasonthey can be found in or near streams and are also resident in talus slopesassociated with road cuts throughout most of their range (Nussbaum et al.1983, Stebbins 1985, Beatty et al. 1991 pers. obser.). Gomez (1992) foundPacific giant salamanders to be most abundant in riparian areas of mature andold-growth forests as compared to upland sites and young and deciduousforests.Ecology and management.-Larval giant salamanders feed upon a widevariety of aquatic invertebrates and vertebrates (fish, tadpoles, and conspecifics).Predators on larval forms include fishes, weasels, water shrews, and othergiant salamanders. Metamorphic individuals have a reputation for beingvoracious predators. Stomach analyses have showed that they eat terrestrialinvertebrates as well as many kinds of vertebrates (snakes, shrews, and birds)(Metter 1963, Nussbaum et al. 1983, Stebbins 1985).The effects of logging on stream amphibians has been examined by Corn andBury (1989). They were able to compare densities of salamanders in loggedversus unlogged reaches of streams in areas where stream gradients were highand low. The major effects of logging on habitats of these salamanders seemsmost severe on low gradient reaches of streams that have been disturbed bytimber harvest. Disturbance adjacent to lower gradient areas in the stream oralong the banks of higher gradient riparian areas allows the deposition ofsediment, which fills cracks and crevices in lower reaches, making the habitatunsuitable. A second effect, apparently limited to cut over areas on highergradient streams is the enhancement of population densities owing to theincreased primary and herbivore production which canopy opening allows(Hawkins et al. 1983). This may be a short term improvement as no long termpublished studies dealing with population dynamics exist.Olympic Salamanders (Rhyacotriton spp.)Range and habitat.-This group of species is the sole member of the subfamilyRhyacotritoninae and ranges from the Olympic Peninsula of northwesternWashington southward to Mendocino, California in humid coastal forests,entirely west of the crest of the Cascade Mountains (Anderson 1968; FigureD.4). This group is comprised of four different species which is soon to berevised by Good and his coworkers.These salamanders are found in and near small, rapidly flowing, well-shadedand permanent streams with clear, cold (usually 60 to 100 C) water (Stebbins1951). They are seldom more than 1 meter from free-running water(Nussbaum and Tait 1977). Small cold (80 to 120 C in summer) streams withwater seeping through moss-covered gravel are preferred habitats. Larvaeoccur in small mountain streams, spring heads and seepages from sea level toabout 1,200 meters (Nussbaum et al. 1983).Ecology and management.-Olympic salamanders apparently require fairlylow ambient temperatures. Adults may occasionally be found under objects a395