Keith Fitzgibbon

Wetland Road Culverts As Amphibian Conduits: an Evaluation of Steel Culverts As Transit Corridorsfor Wetland Amphibians and Small Mammals Keith Fitzgibbon

Linear developments, such as roads, are recognized asmajor contributors to wetland fragmentation. Studieshave shown that the barrier effect of roads result ininbreeding among wetland species and reduced geneticdiversity. For amphibian species, heightened risk oflocal extinction due to population dynamics, anddecreases in the ability of species to re-colonizeotherwise suitable habitat have been cited. This publication examines strategies adopted tomitigate fragmentation effects on sensitive wetlandhabitats. Corrugated steel culverts are evaluated fortheir effectiveness as transit corridors foramphibians and small mammals at Vancouver Islandlocations. Tracks of several species are recorded andanalyzed for occurrences over time. Recommendations are made for improved monitoring ofamphibians and small mammals near roads, and forenhancing the performance of culverts as transitcorridors beneath roads. Comparative trials comparepreferences of the Rough-skinned Newt (Tarichagranulosa) for corrugated steel culvert treatments. Results of the trials show amphibian preferences forthe amount of moisture, the amount of light, andsubstrates used within steel culverts.