Stable isotopes are important tools in various scientific fields, including hydrology, ecology, and geology, to name a few. In ecology specifically, stable isotopes can be used to examine trophic relations. Carbon isotope values are used to trace the source of food. In terrestrial environments, carbon isotopes are useful in differentiating diets based on C3 or C4 plants. Nitrogen isotope values have been used to determine an organism’s specific trophic position. In this study, we use stable carbon and nitrogen isotope values to determine changes in the isotopic composition between source (food) and product (animal tissues) associated with trophic relations. The extent of these changes (fractionations) will be compared with published values.
Several dead animals (goldfish, grasshoppers, crickets, frogs, cockroaches, fruit flies, mealworms, and crayfish) and a sample of their food were kindly obtained from the Biology department at Union College. These were animals that had been used for lab experiments or for faculty and student research. In addition, frozen mice were kindly provided by Prof. Jen Currey. Feathers from window-kill birds, used in a study led by Prof. Jen Bishop, were also included in the study. Finally, pet fur and food samples were kindly provided by Liz Andonie as well as the authors. All samples will be prepared and analyzed in Union College’s Stable Isotope Laboratory, housed in the Geosciences Department.