Meeting Abstract
67.5 Wednesday, Jan. 6 Interspecific variation in behavioral aversion of amphibians to road deicers HAZARD, L.C.*; KWASEK, K.; VIG, D.; Montclair State University., NJ; Montclair State University., NJ; Montclair State University., NJ hazardl@mail.montclair.edu
Winter road deicers (primarily NaCl, but also CaCl2 and other alternatives) may contaminate local watersheds to levels high enough to potentially impact amphibian populations. Amphibians that migrate to vernal pools early in the spring, when salt levels could still be high, may be especially vulnerable. We exposed adult wood frogs (Lithobates sylvaticus), green frogs (Lithobates clamitans), eastern newts (Notophthalmus viridescens), and Couch’s spadefoot toads (Scaphiopus couchii, used to validate methods) to salt solutions to determine whether they could detect and avoid high concentrations of road deicers. Animals were mildly dehydrated to induce thirst, then placed in a shallow dish containing 0-500 mM NaCl or CaCl2. Location (in or out of the dish) and behavior (moving, standing, sitting, or water absorption response) were recorded during a 10-minute trial. A behavioral control trial using distilled water was conducted immediately after each trial; if an animal showed aversion to both the test solution and the control solution the trial was considered unsuccessful and was not used in analyses. Both spadefoot toads and newts showed behavioral aversion to elevated salt concentrations. Green frogs showed a strong escape response during trials, and no successful trials were completed for this species. Wood frogs showed no aversion to NaCl, remaining in even 500 mM solutions despite significant mass loss due to osmotic water loss, and showed aversion to CaCl2 only at the highest concentration. Breeding Wood Frogs may not be capable of evaluating pond salinity, leaving eggs and tadpoles potentially vulnerable to increased mortality or subtler sublethal effects due to road salt runoff.
