Field experiments will be employed to investigate differences in the reproductive biology and population traits of a species of salamander. Different populations of this amphibian exhibit very different growth rates, reproductive rates, and body sizes which appear to be related to differences in environmental quality. This possibility and the alternative that the populations are genetically differentiated will be explored, using a series of experiments in which animals are raised in different environments in the field. Other experiments involve supplementally feeding animals in natural populations to ascertain the specific role of food abundance in determining these traits. Patterns of response to the different conditions will reveal how important the environment is in determining these traits.
