Biodiversity and Altitudinal Variation of Dung Beetles (Scarabaeidae: Scarabaeinae) in the Oglán Alto Watershed, Ecuadorian Amazon

Abstract

Dung beetles are considered a useful taxon to describe and to monitor spatial and temporal patterns of biodiversity. Tropical communities of dung beetles are usually diverse, abundant, and habitat specific; they respond quickly to many types of environmental changes. This study was carried out over 18 months, on an altitudinal gradient in the Oglán Alto watershed, located in Pastaza Province, Ecuador. A total of 10,227 individuals belonging to 59 species were collected. Food preference was analyzed and it was observed that species of coprophagous beetles are superior to necrophagous and generalists species. Tunnelers functional group was more abundant than rollers and dwellers groups, and only this group reduced its richness at higher altitudes. Six richness estimators were used for comparison between the two types of bait used (excrement and carrion). Correspondence Analysis was performed, according to the types of traps and species captured, with respect to the variation of altitudinal gradient. We concluded that the relation of altitudinal gradient and average of richness by traps is very similar among four transects sampled, showing a mixture of species of copro-necrophagous beetles associated to Amazon lowlands, with few species of foothill evergreen forest of the Ecuadorian east. It is recommended to continue studies in this type of vegetation, mainly in a higher altitudinal gradient.