Animal Digestion

Abstract

By Maddie Greenwood, Archaeology and Anthropology

Advisor: Brooke Crowley

Presentation ID: PM_ATRIUM19

Abstract: I examined the influence of digestion on the isotopic composition of animal tissue. Stable isotope values provide information about an animal's diet and habitat. Analyzing isotope values in consumed prey may be particularly useful approach for monitoring habitat use by difficult to observe, solitary, or rare animals. However, there is little known about how digestion influences isotope values, particularly for birds. Carbon and nitrogen isotope values (_13C and _15N respectively) were examined in tissues from prey (both pre and post digestion) for three predator species at the Cincinnati Zoo: an eagle owl (Bubo bubo), red-tailed hawk (Buteo jamaicensis), and a serval (Leptailurus serval). Samples were collected from each individual's enclosure for three consecutive days. I analyzed fur/ feathers, bone and muscle, as well as fecal matter, as available. All samples were processed and analyzed at the UC Stable Isotope Biogeochemistry Facility. Upon initial inspection of the data, isotope values in both fur and bone were affected by digestion. For most prey, isotopic shifts were small (<1?) but some samples had larger shifts of (2+?). Predator fecal matter tended to have lower _13C values than prey tissues, while fecal _15N values were more variable.