Macroimmunology: the drivers and consequences of spatial patterns in wildlife immune defense

1. Spatial variation in parasite pressure, abiotic and biotic conditions, and anthropogenic factors can all shape immune phenotypes across spatial scales. Identifying the most important spatial drivers of immunity could help preempt infectious disease risks, especially in the context of how large-scale factors such as urbanization affect defense by changing environmental conditions. 2. We provide a synthesis of how to apply macroecological approaches to the study of ecoimmunology (i.e., macroimmunology). We first review spatial factors that could generate spatial variation in defense, highlighting the need for large-scale studies that can differentiate competing environmental predictors of immunity and detailing contexts where this approach might be favored over small-scale experimental studies. We next conduct a systematic review of the literature to assess the frequency of spatial studies and to classify them according to taxa, immune measures, spatial replication and extent, and stat...