Following the dung or the climate? Species richness pattern of dung beetles (Scarabaeinae) on the Americas
AbstractClimatic conditions are a main driver of species richness. Specifically, increase on climatic instability may reduce species richness directly and indirectly by reducing resources available. This hypothesis is evaluated here using a producer- consumer interaction to explain dung beetle richness on a continental scale (America) using mammal richness as resource proxy and temperature and precipitation seasonality as proxy for climatic instability. A spatial path analysis was built in order to evaluate this hypothesis while controlling for spatial autocorrelation and differences on the sampling effort and abundance of each study (n=115) gathered from the literature. Dung beetle richness was directly explained by temperature seasonality, precipitation seasonality and mammal richness, whereas only precipitation seasonality had an effect modulated by mammal richness. This result reinforces the notion that species richness can be explained by climatic conditions, but also reveals the importance of biotic interactions in order to understand the mechanisms behind such patterns.