Metabolic and microbial changes in light-vented bulbul during recent northward range expansion

Abstract Endotherms recently expanding to cold environments generally exhibit strong physiological acclimation sustain high body temperature. During this process, gut microbes likely play a considerable role in host functions, including digestion and thermogenesis. The Light-vented bulbul Pycnonotus sinensis represents one of such species. It used be restricted the Oriental realm, but expanded its distribution range north Palearctic areas during past few decades. Here, we explored seasonal dynamics resting metabolic rate (RMR) microbiota for local newly colonized populations Our results showed that mass-adjusted RMR mass were positively correlated with latitude variations both seasons. Consistently, corresponding variation northern environments. In two populations, alpha diversity decreased compared those southern populations. Significant differences detected dominant phyla, as Firmicutes, Bacteroidetes, Proteobacteria Desulfobacterota core geographic winter, elevated relative abundance 5 species Finally, explore link between microbial communities thermogenesis, conducted correlation analysis RMR. We found more genera significantly wintering season breeding (71 versus 23). These suggest lighted-vented linked thermogenesis under northward expansion.