Host diversity outperforms climate as a global driver of symbiont diversity in the bird-feather mite system

Aim: The simultaneous influence of abiotic and biotic factors as main drivers of global species distributions remains poorly understood, especially in host-dependent groups. In this study, we diverge from traditional macroecological approaches by considering both biotic (avian species diversity) and abiotic (climatic) factors in determining the global distribution pattern of feather mite species richness, one of the most abundant and diverse bird ectosymbionts.

Location: Global.

Methods: We used a global dataset of feather mite-bird interactions published in 2016, complemented with an up-to-date literature survey. We created statistical models designed to explain the effect of abiotic (i.e., temperature, precipitation, and energy-related variables) and biotic factors (bird species richness) on the species richness of feather mites. We used these models to predict global distribution patterns of mites and estimate each explanatory variable’s relative importance in temperate and tro...