Modeling the Effects of Environmental Influences on the Phenotypic Plasticity of the Tiger Salamander

Tiger salamanders are commonly found throughout North America. The live in and around ponds, slow streams, marshes, and other wetlands during the spring and fall and dig burrows in prairies, fields, and forests during the dryer months. Tiger salamanders demonstrate polyphenism, which is described as an occurrence of two or more phenotypes within a species whose variation steer development down one pathway or another because of differences that occur in the species environment. Tiger salamanders come in two different immature forms: (1) a typical aquatic larva, and (2) a cannibal form. Typical larvae feed on small pond invertebrates while the cannibal larvae will feed on larger vertebrates including other tiger salamanders. The two types are genetically identical as, the cannibal form develops from typical larvae when the social environment becomes suitable for the cannibalistic form. A suitable environment is one in which many salamanders larvae live together and the size of larvae vary greatly giving the largest individuals access to an abundant food source and the opportunity to grow larger. Tiger salamanders can recognize their kin and are less likely to develop into cannibals in ponds of relatives. By using competition models and computer simulations, we will be able to use research conducted on salamander populations to compute models that will help us discover density thresholds that can turn a typical larvae salamander into a cannibal