Distribution and habitat of Rhyacotriton variegatus in managed, young growth forests in north coastal California

We examined the distribution and habitat of Rhyacotriton variegatus in streams of managed forests in north coastal California. We found 1475 salamanders from 220 streams from 1990-1994 through surveys of randomly selected first and second order streams and incidental searches. Of 71 headwater streams randomly selected to relate landscape variables to the presence/absence of R. variegatus, 57 (80.3%) contained salamanders. Geological formation was the only landscape variable that predicted the presence of R. variegatus in a stepwise logistic regression model. A second survey was conducted to determine which habitat variables of stream reaches were related to the presence/absence of R. variegatus. Thirty-one of 64 stream reaches contained salamanders and stream slope (gradient) was the only variable of 20 measured that entered a stepwise logistic regression model to predict the presence of R. variegalus. Pairwise comparisons indicated that reaches with salamanders had significantly higher slope, more small boulders, and less sand. No other variables, including canopy closure and water temperatures, were significant. An additional survey to further define the microhabitat for R. variegatus showed that abundance was positively related to stream slope and that this species was found more often than expected in high gradient riffles. The preferred substrate was gravel with smaller amounts of silt/clay, sand, and cobble. We discuss the past and future impacts of timber harvest on this species in north coastal California.