Is there evidence of amphibian decline and malformations in two species of urban toads, Bufo americanus and Bufo woodhousei, during a two year study

This thesis explores the question of amphibian decline in urban populations of two specific species. It reviews the literature on the evidence for amphibian decline and malformation as well as the suspected causes. It includes a two year study of urban toads and documents their decline using the Lincoln Peterson Index during a two year period. The circumstantial evidence in this thesis indicates that the decline of the toad populations may have occurred when the toads were exposed to heavy applications of the pesticide, methoprene. It also documents a significantly high rate of amphibian malformation in the two species of toads living within a New York City Park and includes photographs of the types of malformations found. The thesis further explores the effects of nitrate exposure on larval toads and the possible effects of methoprene on toad hibernation survival. The effects of nitrates on larval toads was found to be insignificant. However, the effects of methoprene on toads is of major environmental concern. The final chapter of the thesis discusses the importance of field studies to the earth and environmental science educator and the reason they should be included in the teaching of these sciences in particular.