Three Pathogens Impact Terrestrial Frogs from a High-Elevation Tropical Hotspot

Three infectious pathogens Batrachochytrium dendrobatidis (Bd), Ranavirus (Rv) and Perkinsea (Pr) are associated with widespread and ongoing amphibian population declines. Although their geographic and host ranges vary widely, recent studies have suggested that the occurrence of these pathogens could be more common than previously thought, even in direct-developing terrestrial species traditionally considered less likely to harbor these largely aquatic pathogens. Here, we characterize Bd, Rv, and Pr infections in direct-developing terrestrial amphibians of the Pristimantis genus from the highland Ecuadorean Andes. We confirm the first detection of Pr in terrestrial-breeding amphibians and in the Andean region, present the first report of Rv in Ecuador, and we add to the handful of studies finding Bd infecting Pristimantis. Infection prevalence did not differ significantly among pathogens, but infection intensity was significantly higher for Bd compared to Pr. Neither prevalence nor intensity differed significantly across locality and elevation for Bd and Rv, although low prevalence in our dataset and lack of seasonal sampling could have prevented important epidemiological patterns from emerging. Our study highlights the importance of incorporating pathogen surveillance in biodiversity monitoring in the Andean region and serves as starting point to understand pathogen dynamics, transmission, and impacts in terrestrial-breeding frogs.