Habitat and seasonal drivers of leukocyte profiles within and across Neotropical bat species

Land conversion is a dominant form of environmental change that can alter infection dynamics in wildlife by affecting host immune defense. Such effects may be compounded by seasonal variation in resources and reproduction and vary among members of a host community, yet the combined effects of habitat, season, and species identity on wildlife immunity remain poorly understood. We tested within- and across-species effects of land conversion and seasonality on immunity in Neotropical bats by quantifying hematological markers of physiological stress and inflammation. We sampled seven species across a large preserve and a smaller forest fragment in northern Belize during both the dry and wet seasons. Using phylogenetic generalized linear mixed models, we tested the overall effects of habitat and season and quantified per-species impacts. Total white blood cell counts and neutrophil-to-lymphocyte ratios showed no overall habitat or seasonal effects but displayed strong species-specific responses. In contrast, the systemic inflammation response index increased across all species in the dry season and smaller fragments, suggesting general poor health in unfavorable conditions. Species-specific effects did not align with dietary guilds, indicating roles for finer-scale ecological traits. Our findings highlight the complex, species-dependent effects of environmental change on wildlife's immune defense.