Friday, August 6, 2010

PS 87-11: Potential impact of human transportation on amphibian and reptile populations

Christina Soman, Jikai Xu, and Meiyin Wu. Montclair State University

Background/Question/Methods

In spring, amphibians and reptiles emerge from their wintering locations in the woods and migrate to nearby ponds or pools in order to breed.  Their migration pathways are often intersected by roadways commonly referred to as crossways.  High mortalities caused by transportation are often identified at the crossways during the migration season.  This project aims to study wildlife mortality caused by human transportation. 24 pitfall traps (5 gallons in size) were installed at approximately 15 feet from the roadway.  Traps were placed at 25 ft intervals along a silt fence parallel with the roadway. Organisms found in the traps were recorded twice a day at 12 hour intervals. Daily temperature and precipitation data were obtained from the New Jersey Weather and Climate Network.

Results/Conclusions

Between 3/14 and 5/6/2010, 668 organisms across 12 species were recorded including American toad (Bufo americanis), bull frog (Rana catesbeiana), chorus frog (Pseudacris triseriata), Fowler’s toad (Bufo fowleri), green frog (Rana clamintans), northern grey tree frog (Hyla versicolor), spring peeper (Pseudacris crucifer), wood frog (Rana sylvatica), red spotted newt (Notophthalmus viridescen), spotted salamander (Ambystoma maculatum), snapping turtle (Chelydra serpentina), and eastern garter snake (Thamnophis sirtalis).  The most dominant species was American toad at 70%.  Green frog, red-spotted newt and spring peeper were also abundant.  Previous studies documented 19 to 25% amphibian and reptile mortality caused by human transportation during the migration season; during the eight-week study period, human transportation had a potential to kill up to 160 amphibians and reptiles within a 600 ft segment of a two-land roadway in a New Jersey suburban area.