Meeting Abstract
P3.38 Thursday, Jan. 6 Interspecific variation in behavioral aversion of sympatric temperate zone amphibians to road deicers HAZARD, L.C.; KWASEK, K.M.*; KOELMEL, E.; GERGES, S.; Montclair State University, New Jersey; Montclair State University, New Jersey; Montclair State University, New Jersey; Montclair State University, New Jersey kwasekk1@mail.montclair.edu
Contamination of vernal pools and other bodies of water by winter road deicers has been shown to impact larval amphibian survival, but adult responses to deicer contamination are less well-known. We tested adults of four sympatric amphibian species from the northeastern United States using choice trials to determine whether they showed aversion to road deicers (primarily NaCl, but also CaCl2 and other alternatives), and if so, at what threshold concentration. Individuals of two obligate vernal pool-breeding species, wood frogs (Lithobates sylvaticus) and spotted salamanders (Ambystoma maculatum), and two non-obligate vernal pool breeders, green frogs (Lithobates clamitans) and eastern newts (Notophthalmus viridescens), were placed in a test chamber containing aged tap water on one side and a test solution on the other. Location and behaviors were recorded during a 10-minute trial. Each animal was tested at several concentrations (0 to 500 mM) of NaCl or an alternative deicer in a repeated measures design, with at least three days of recovery between trials. EC50 values (threshold concentration at which half of the animals showed aversion, defined as spending less than 5 min in the test solution) were calculated from logistic curve fits. Species differences in threshold concentrations were observed; in particular, wood frogs showed no aversion to any NaCl concentration tested. Animals showed greater aversion to other cations (CaCl2 and MgCl2 solutions) than to sodium. Species with higher behavioral thresholds may attempt to breed in habitats unsuitable for successful egg and larval development. These results will help predict future impacts of increased habitat salinity on amphibian communities.
