EVIDENCE OF A NEW NICHE FOR A NORTH AMERICAN SALAMANDER: ANEIDES VAGRANS RESIDING IN THE CANOPY OF OLD-GROWTH REDWOOD FOREST

We investigated habitat use and movements of the wandering salamander, Aneides vagrans,in an old-growth forest canopy. We conducted a mark-recapture study of salamanders in the crowns of five large redwoods (Sequoia sempervirens) in Prairie Creek Redwoods State Park, California. This represented a first attempt to document the residency and behavior of A. vagrans in a canopy environment. We placed litter bags on 65 fern (Polypodium scouleri) mats, covering 10% of their total surface area in each tree. Also, we set cover boards on one fern mat in each of two trees. We checked cover objects 2-4 times per month during fall and winter seasons. We marked 40 individuals with elastomer tags and recaptured 13. Only one recaptured salamander moved (vertically 7 m) from its original point of capture. We compared habitats associated with salamander captures using correlation analysis and stepwise regression. At the tree-level, the best predictor of salamander abundance was water storage by fern mats. At the fern mat-level, the presence of cover boards accounted for 85% of the variability observed in captures. Population estimates indicated that individual trees had up to 29 salamanders. Large fern mats have high water-holding capacities, which likely enable year-round occupation of the canopy by A. vagrans. Other observations indicate that A. vagrans and its close relative A. ferreus also occupy additional habitats in forest canopies, especially moist cavities inside decaying wood.