Effects of Stormwater Ponds on Calling Amphibian Communities in Monroe County, NY

Abstract

Many studies have investigated how urbanization affects calling amphibians and how stormwater retention ponds are utilized by anurans. Few studies, however, have investigated the combined effects of land use and within-pond conditions on these species. Thus, I studied calling amphibian communities at 38 stormwater ponds in Monroe County, NY to determine which factors at the local and landscape scale affected anuran presence, community composition, and breeding. I used aural surveys following Marsh Monitoring Program protocol to record presence and relative abundance and visual encounter surveys for signs of breeding. I used GIS to determine land use and also measured water quality and other habitat features within the ponds. I then used information theory to determine best models for my response variables. American toad (Anaxyrus americanus) presence and spring peeper (Pseudacis crucifer) call code both responded negatively to increase in impervious area and loss of wooded habitat. Green frog (Lithobates clamitans) abundance and calling intensity were both negatively related to specific conductance and positively related to emergent vegetation cover. Bullfrog (Lithobates catesbeianus) calling intensity was also negatively related to specific conductance. Sites with high species richness associated most strongly with the absence of fish and responded negatively to higher pH, noise pollution, more impervious surface, and less upland habitat. Evidence of breeding was also lower at sites with more impervious surface and less terrestrial habitat. My results suggest that species respond differently to selective pressures within the pond and surrounding landscape, largely due to differences in life history characteristics. When designing ponds to support diverse amphibian assemblages, ponds should be placed away from impervious surface and adjacent to woodlots. Ponds should be managed as groups rather than individually to ensure habitat requirements of individual species are being met, as well as to support source-sink dynamics.