Abstract: The invasion of pathogens to new regions has caused widespread population declines and driven species to extinction. The emergence and establishment of white-nose syndrome (WNS), a fungal disease of bats, provides an opportunity to examine disease dynamics across a gradient of pathogen invasion to understand the multitude of factors that contribute to host-pathogen coexistence. We used individually-based bat infection data collected over the 10-year period of WNS invasion and establishment to address the question: How have host-pathogen dynamics changed since the arrival of WNS, and how do they contribute to host-pathogen coexistence? We find that both changes in the environment and host traits contribute to the persistence of bats with WNS. First, temperature- dependent growth of the fungus selectively removed bats roosting at the warmest temperatures and resulted in a population-level shift toward cooler roosting conditions. The preferential survival of bats at the coolest temperatures resulted in overall reductions in pathogen growth on bats. However, bats also evolved host traits that facilitated their survival, including the development of resistance that allowed them to further reduce fungal growth and increased their survival. Interestingly, the importance of specific traits (e.g. body condition) appeared to change with disease phase such that some traits appear important in surviving the initial epizootic but their importance diminishes as the pathogen establishes. Collectively, our results suggest that bat survival in the face of global change will likely require rapid adaptation and a more comprehensive understanding of factors that aid in population health.