Influence of gallery forests fragmentation in the Colombian Orinoquia on the diversity and functional structure of the dung beetles’ assemblage

Abstract

The gallery forests of the Colombian Orinoquía have suffered strong fragmentation processes that have affected their fauna and especially the primate populations. However, studying mammals is extremely complex and expensive. Using the close relationship that exists between the diversity and abundance of mammals and dung beetles, it is proposed to use this group as a tool to evaluate this effect. In order to understand how the size of forest fragments and associated primate fauna affect the diversity and structure of the dung beetle assemblage, a study was conducted on four fragments of different sizes. Linear transects of pitfall traps baited with excrement were located. The diversity and structure of the assemblage were evaluated, and an analysis of variance was carried out to determine differences between the fragments. A total of 1172 individuals, 18 species, and 11 genera were collected. There was evidence of a decrease in richness, abundance, and number of functional groups from the largest fragment (17 spp.) to the smallest fragment (7 spp.). The low richness found would indicate a negative effect of fragmentation, where the size of the forests is critical to maintain their diversity. The small fragments do not manage to maintain their diversity or a functional structure with the disappearance of large paracoprids and telecoprids, showing that beetles are an efficient indicator of the anthropic effects in this ecosystem. Finally, it can be concluded that the gallery forest fragments of the Colombian Orinoquía constitute a wildlife refuge that must be preserved.