Clay models and eDNA are useful tools for identifying predators of Salamanders

Clay models are a popular technique for studying predation in nature due to their ease of deployment and minimal disruption of natural processes, but a drawback is the ambiguity of identifying predators based on bite marks. However, it is possible to amplify and sequence environmental DNA (eDNA) from these bite marks and to identify the predators responsible for attacking models. In this study, we sought to test the viability of eDNA from clay models as a means of identifying predators. We deployed molded clay models that resemble Plethodon ventralis Highton (Southern Zigzag Salamanders) into the field. We then extracted eDNA from visible bite marks, amplified and sequenced the 12S rRNA mitochondrial locus on an Illumina MiSeq, and used BLAST to determine the identity of representative sequences. We identified likely predators as Procyon lotor L. (American Raccoons), Didelphis virginiana Kerr (Virginia Opossums), Turdus migratorius L. (American Robins), and Tamias striatus L. (Eastern Chipmunks). We believe that this technique is helpful for adding a layer of specificity to clay model studies, albeit with a few potential pitfalls that we discuss.