Amphibians in a protected landscape: A 30 year assessment

Abstract/Summary

Determining where animals are and if they are persisting across protected landscapes is necessary to implement appropriate management and conservation actions. For long-lived animals and those with boom and bust life histories, perspective across time contributes to discerning temporal trends in occupancy and persistence and potentially in identifying mechanisms affecting those parameters. Long-term data are particularly useful in protected areas where change may be less obvious. We used long-term amphibian data specific to Rocky Mountain National Park in a Bayesian occupancy modeling framework to estimate changes in colonization and persistence of amphibians over three decades and explored mechanisms (e.g., precipitation, drought, visitor use) behind observed changes. Our results indicate that colonization is low and the probability of persistence is declining for Pseudacris maculata, Lithobates sylvaticus and Ambystoma mavortium; and that occupied catchments are increasingly isolated. We found visitor use to be the most influential mechanism, negatively affecting occupancy and persistence of amphibians in RMNP. While these results are sobering, they also provide a way forward where mitigation efforts can target identified drivers.