Surveys of Eastern Hellbender (Cryptobranchus a. alleganiensis) Populations in Central Pennsylvania Using Environmental DNA: Optimal Time and Season Sampling Assessment

Mayu Uemura

Abstract

Studies have shown that eastern hellbenders are one of many amphibian species that have been experiencing population declines in recent years. Due to their secretive characteristics, there are no up-to-date and reliable hellbender population range records for central Pennsylvania (PA). Therefore, we conducted eDNA surveys to assess the current habitat range and population status of C. alleganiensis in central PA. Using eDNA assays followed by qPCR, we aimed to 1) provide a more accurate habitat range estimate for C. alleganiensis than a traditional physical survey, and 2) find the optimal time of a day and season for hellbender population surveys. We detected hellbender eDNA from positive control streams, indicating reliability of the survey. We also identified several new sites that are likely to house hellbender populations. We obtained highest concentrations of hellbender eDNA during September sampling, indicating a higher activity of hellbenders in their breeding season. eDNA surveying is a useful method to provide information for hellbender conservation.