Host traits and environment interact to determine persistence of bat populations impacted by white‐nose syndrome

Emerging infectious diseases have resulted in severe population declines across diverse taxa. In some instances, despite attributes associated with high extinction risk, disease emergence and host declines are followed by host stabilisation for unknown reasons. While host, pathogen, and the environment are recognised as important factors that interact to determine host–pathogen coexistence, they are often considered independently. Here, we use a translocation experiment to disentangle the role of host traits and environmental conditions in driving the persistence of remnant bat populations a decade after they declined 70–99% due to white‐nose syndrome and subsequently stabilised. While survival was significantly higher than during the initial epidemic within all sites, protection from severe disease only existed within a narrow environmental space, suggesting host traits conducive to surviving disease are highly environmentally dependent. Ultimately, population persistence following pathogen invasion is the product of host–pathogen interactions that vary across a patchwork of environments. Following the invasion of novel and virulent pathogens, some host populations coexist with pathogens while others decline to extinction. Here, we use a translocation experiment to identify interacting mechanisms by which bat populations persist with white‐nose syndrome. We find that unique host traits have evolved since pathogen invasion and contribute to persistence, but that the degree of protection afforded is environmentally dependent.