Integrating Stable Isotopes and DNA Metabarcoding of Cave Guano to Develop a Unique Paleoenvironmental Archive for the Humid Tropics 

The goal of our project is to gain a better understanding of how vegetation coverage has changed over the last several thousand years in Costa Rica so that we can make more informed decisions about how to restore tropical forests and how to conserve biodiversity. We will do this by analyzing the contents and chemistry of modern and ancient bat guano, which preserves information about bat diet as well as the climate and environment the bats experienced. First, we will collect modern bat guano to characterize the diet of the insectivorous Parnell’s mustached bat (Pteronotus parnellii). We will examine DNA retained in the guano to identify the species of insects the bats consumed and isotope analyses to quantify the relative importance of those different species to bat diet. We will then collect samples from a vertical core taken from the guano layers accumulated over 3-5 thousand years and use our knowledge of modern bat diet to interpret ancient guano chemistry (carbon and nitrogen isotope values).

Publications

Reid, R.E.B., J.T. Waples, D.A. Jensen, C.E. Edwards, and X. Liu. (2022). Climate and vegetation and their impact on C and N isotope ratios in bat guano, Frontiers in Ecology and Evolution. doi.org/10.3389/fevo.2022.929220

Research Team

Xinyi Liu, WashU (Anthropology)
Christy Edwards, Missouri Botanical Garden
Rachel Reid, WashU (Anthropology)
J. Leighton Reid, Missouri Botanical Garden
Bronwen Konecky, WashU (Earth and Planetary Sciences)