Variation in dung removal by dung beetles in subtropical Atlantic Rainforests

Dung consumption and removal is a fundamental ecological process carried out by dung beetles that drive soil nutrient cycling and associated ecosystem services. In this study, the removal rate of small droppings by dung beetles was estimated in natural subtropical rainforests of southern Brazil located along an elevational gradient, in order to understand the factors influencing variation in dung removal. To do that, the comparative explanatory capacity of three main types of variables was quantified: assemblage characteristics, local climatic and habitat conditions, and seasonal variation. The complete disappearance of dung within 48 h after deposition occurs in 73% of occasions. The highest explanatory capacity correspond to the combined effects of the three types of variables; however, average air temperature during the sampling period, total volume of dung beetles collected in the traps in which dung removal was measured, and the seasonal transition from summer to winter were the most important and representative predictors of dung removal. Thus, the dung nutrient incorporation into the soil will most likely be greater during spring-summer conditions, when the air temperature at the time of dung deposition is high and the biomass of the dung beetle assemblage is bigger.