Bigger and stronger bury deeper: the role of dung beetles as secondary seed dispersers in the northern Colombian Andes

Ecosystem services as seed dispersal mediated by insects are threatened by increasing agricultural expansion that represents a global threat. Although the ecological role of dung beetles as secondary seed dispersers has been well-documented, few studies have focused on the effect of taxonomic and functional attributes of dung beetles in human-dominated landscapes. We analysed how the seed size, the diversity of the dung beetles and some of their functional traits (body size, length of the hind legs and relocation strategy) affect the depth and quantity of seeds buried and abundance and richness of beetles at different depths in a forest in the Colombian Andes. We used plastic cubes buried in the ground (mesocosms) to study ecosystem functions of dung beetles. We collected 397 individuals representing 13 species within the mesocosms. The most abundant species of dung beetle collected was Canthidium sp. 1 with 152 individuals. Of the total seeds collected, 91% of the total seeds used were buried, and the small ones were buried in a greater proportion than the larger ones. Seed size did not influence burial depth, but beetle taxonomic attributes did, but only for large seeds. Burial depth was positively related to beetle richness and abundance, as well as to body size. Large beetles buried more seeds and buried them deeper. We highlight the importance of Dichotomius aff. satanas as a key seed disperser of Andean riparian forests. We emphasize that this beetle actively participated in seed dispersal, and that this ecological function depended on the taxonomic and functional attributes of the dung beetle species.