PARENT SESSION
Poster Session 32: Reptiles and Amphibians.
Thursday, August 5 Presentations from 5:00 PM to 6:30 PM, Exhibit Hall A 1.
Roads are partial barriers to dispersal of terrestrial salamanders.
BECKMAN, NOELLE*,1, MILAM, GRAHAM 1, GORHAM, NICHOLAS1, MARSH, DAVID1, 1 Washington and Lee University, Lexington, VA, 24450
ABSTRACT- One of the primary effects of habitat fragmentation is the isolation of populations in fragments separated by harsh matrix areas. However, the extent to which different landscape elements are actually dispersal barriers is often unknown. We asked whether forest roads are barriers to dispersal of red-backed salamanders, Plethodon cinereus. We marked and displaced over 1500 salamanders at 5 road sites. At each site, salamanders were displaced across the road or an equal distance into the forest. We then used the relative return rates of these two grops as an index of the barrier effects of roads. Roads reduced return rates by an average of 50% percent across all five sites. However, these barrier effects were highly variable from site to site. Variability did not appear to be related to road surface - the two paved sites had both the highest and the lowest return rates. However, sites with steeper road cut banks had lower return rates. Surprisingly, this reduction appeared to be due to reduced movements down steep banks, rather than reduced movement up these banks. Our results suggest that roads are partial barriers to salamander dispersal, but that roads through flat areas should have substantially lower barrier effects than roads on hillsides that produce steep cut banks.
Key words: roads, salamanders, fragmentation , dispersal