Interactions between seeds and dung beetles (Scarabaeinae) in a tropical dry forest

Abstract

Dung beetles (Scarabaeinae) are important insects in many terrestrial ecosystems due to their ecological functions, which are a consequence of their dung-burying behavior. This insect group is particularly abundant in tropical forests (TF). Yet, their ecological functions have been studied more extensively in humid TF and little information is available for dry TF. We carried out field experiments in the Chamela Biological Station (Jalisco, México) during the rainy season to quantify dung removal by Scarabaeinae as well as the interactions with seeds that occur as a consequence of dung removal in a dry TF. After 48 h dung removal was complete; 71% of artificial seeds were buried between 0.5 and 30 cm of depth, and 29% remained on the surface but dispersed horizontally between 1 and 150 cm. The establishment of seedlings from the soil seed bank was enhanced by the presence of dung and the activity of dung beetles. Comparing our results with those obtained in humid neotropical forests we conclude that in the studied dry forest, during the rainy season, the ecological functions of Scarabaeinae are similar to those registered in humid TF.