Stable isotope analysis is a technique that has been used extensively to explore food webs and the diets of various aquatic and terrestrial animals. Although any tissue can be used, in this study we use mammal fur, which can be collected using minimally invasive techniques. We conducted stable isotope analysis of the fur of twenty-six wild mammals captured in a variety of locations in the Capital District, including Featherstonhaugh State Forest and Union College in Schenectady County, the Albany Pine Bush Preserve in Albany County, and Glenwild Preserve in Saratoga County. Species include: northern short-tailed shrews (Blarina brevicauda), red squirrels (Sciurus vulgaris), and gray squirrels (Sciurus carolinensis). These data will be combined with existing data in the LoGiudice lab to explore differences between species and locales. Intended comparisons include short-tailed shrews from a residential basement with wild shrews, red squirrels vs. gray squirrels and rodents vs. insectivores.