Environmental DNA (eDNA) collection has emerged as a powerful and noninvasive wildlife population and pathogen‐monitoring tool. Ranavirus is an emerging pathogen linked to die‐offs in amphibian species. Applications of eDNA detection for ranavirus surveillance have shown promise, but it is unclear how reliably eDNA represents viral pressure on host populations. We evaluated the relationship of ranavirus titers in hosts and eDNA in four New York vernal pools from May to October 2016. We compared ranavirus titers in aquatic eDNA samples (n = 562) and liver samples (n = 362) of wood frog (Lithobates sylvaticus) and green frog (Lithobates clamitans) larvae from pools with past ranavirus die‐offs. We detected low‐quantity Ranavirus DNA (

Amphibian ranaviruses occur globally, but we are only beginning to understand mechanisms for emergence. Ranaviruses are aquatic pathogens which can cause > 90% mortality in larvae of many aquatic-breeding amphibians, making them important focal host taxa. Host susceptibilities and virulence of ranaviruses have been studied extensively in controlled laboratory settings, but research is needed to identify drivers of infection in natural environments. Constructed ponds, essential components of wetland restoration, have been associated with higher ranavirus prevalence than natural ponds, posing a conundrum for conservation efforts, and emphasizing the need to understand potential drivers. In this study, we analyzed 4 years of Frog virus 3 prevalence and associated environmental parameters in populations of wood frogs (Lithobates sylvaticus) and green frogs (Lithobates clamitans) in a constructed pond system. High prevalence was best predicted by low temperature, high host density, low zooplankton concentrations, and Gosner stages approaching metamorphosis. This study identified important variables to measure in assessments of ranaviral infection risk in newly constructed ponds, including effects of zooplankton, which have not been previously quantified in natural settings. Examining factors mediating diseases in natural environments, particularly in managed conservation settings, is important to both validate laboratory findings in situ, and to inform future conservation planning, particularly in the context of adaptive management.Electronic supplementary materialThe online version of this article (10.1007/s10393-018-1350-5) contains supplementary material, which is available to authorized users.