Graduation Year


Document Type

Campus Only Senior Thesis

Degree Name

Bachelor of Arts



Reader 1

Donald McFarlane

Reader 2

Sarah Gilman


This paper investigates bat guano, the digestive waste of bats, as a potential indicator of surrounding environmental conditions. In 2021, 8 guano samples were collected and later dried out and dissolved in preparation for analysis. Initially, Inductively Coupled Plasma Optical Emissions Spectrometry (ICP-OES) to test for cadmium, mercury, and lead content, but a majority of the results were below detection limits and the samples were subsequently sent off to ActLabs where they used Inductively Coupled Plasma Mass Spectrometry (ICP-MS) which is more sensitive to lower concentrations. Data was analyzed by comparison to previous studies using mainly graphical, visual, and literary analysis. Looking at correlations between metal concentrations, there wasn’t any correlation between cadmium and mercury, which was expected, but there was a correlation between concentrations of mercury and lead which was didn’t have any precedent in previous studies. The strongest correlation was between lead and cadmium concentrations which was consistent with findings from previous studies, and this is likely because lead and cadmium come from a lot of the same sources. There were no clear patterns found between the concentrations of different metals and either the species of bat or the location of collection, but the limited amount of data prevents any conclusive findings on the matter. All of the collected data fell within the ranges of previous studies. These results suggest that these findings are reliable and that the concentrations found in the bat guano may be a reflection of their surroundings.

This thesis is restricted to the Claremont Colleges current faculty, students, and staff.