Perching behavior by dung beetles (Coleoptera: Scarabaeidae): A spatial segregation mechanism to dilute interspecific competition in highly rich assemblages?

Sit-and-wait is a common strategy to optimize time and energy devoted to foraging activities. Among Coleoptera, dung beetles are one of the groups that display this behavior. Although diverse aspects of natural history have been reviewed, no agreement exists on which theory may explain this food searching tactic. We performed a systematic literature review about this behavior in dung beetles, analyzing existing studies, and discussing potential explanations. We identified six different hypotheses (resource partitioning, food detection, foraging time, predator's avoidance, thermoregulation, and resting). Based on the evidence that we found, we support the hypothesis that the main driver of perching behavior is a strategy of spatial segregation. We found reports for several tribes in different biogeographical regions, especially in Neotropical forests. Few studies explore the relationship between perching height and dung beetles' size. However, recent findings sustained that dung beetles perch at a height proportional to its size, large beetles prefer bigger leaves, and functional groups perch at different heights. Dung beetles observed perching were strictly coprophagous and there is no specific relationship between dial activity and perching behavior. We also found perching records of the three main functional guilds (tunnelers, rollers, and dwellers). Despite several studies of dung beetles perching, there is a lack of experimental analyses. One aspect to analyze in future investigations is the relationship between perching behavior and functional traits. Finally, it is essential to explore and solve some questions that we propose to understand the functional role of this behavior in the structure of assemblages.