Abstract
Understanding the mechanisms of viral co-infection in natural host populations is crucial for predicting pathogen dynamics and cross-species transmission risks. This study focuses on the co-infection of avian influenza virus (AIV) and Newcastle disease virus (NDV) in wild ducks, combining field monitoring data, ecological niche modeling, and statistical analysis to reveal distribution patterns and driving factors. Organ samples collected from wild ducks in key migratory habitats revealed that AIV exhibits a broader ecological niche than NDV, with both viruses primarily replicating in the respiratory system. Ecological niche overlap modeling indicated a high degree of preference overlap between AIV and NDV in organ-specific microenvironments, suggesting that ecological compatibility is a prerequisite for co-infection. This study underscores the critical role of ecological and spatial compatibility in shaping viral co-infection patterns and provides a theoretical framework for understanding virus interactions in complex ecosystems.