Tue, Aug 03, 2021:On Demand
Background/Question/Methods
Dung beetles (Scarabeinae) are present on all continents except Antarctica, and provide many important ecosystem services such as, nutrient recycling, soil aeration, improved biodiversity of soil microbiome, improved nitrogen transport to soil, parasite and pathogen control, and they function as secondary seed dispersers. Scarabeaniae or the dung beetle subfamily has ~6000 species and 200 genera, of those ~1,200 species are found in the Neotropics, though this number will likely increase with more comprehensive biodiversity studies.
Dung is both uncommon with respect to other commonly used resources (i.e. plants), and undefended, suggesting that dung beetles should be physiologically capable of eating all kinds of dung. The most common method used in dung beetle studies is pitfall trapping, which measures attraction but eliminates many natural variables, such as acceptance of dung, competition for dung, natural size of dung, and limited number of bait types (e.g many fewer baits than mammal species in the forest). These limitations could be resolved with a more direct study of dung beetle diets.
We are advancing the methods needed to extract mammal DNA from dung beetle guts to more precisely understand dung beetle diets. We wash and dissect the beetles then extract the DNA and amplify target mammal DNA from the guts using mammal specific primers for 12s and 16s mitochondrial genes.
Results/Conclusions Or preliminary results show that dung beetles caught in pitfall traps can be used to create dung beetle mammal networks. First network based on dung beetle molecular gut content analysis (60) beetle individuals from pitfall traps, and hand collections. These include successful amplification from 5 species of dung beetles, and 8 species of mammals from multiple feeding guilds. Our preliminary results suggest that common diurnal species foraged on dung from all primate species present in the area (howler, spider and capuchin monkeys) that are active during the day, whereas nocturnal Deltochilum sp. beetles included jaguar, margay and puma dung, as well as armadillos which are more night active mammals. Such dial partitioning contributes to overall network specialization (H2’ =0.42). In addition, to the importance of studying mammal dung beetle networks this method could improve upon standard methods for surveying mammal diversity, by requiring fewer man hours and better species coverage.
Results/Conclusions Or preliminary results show that dung beetles caught in pitfall traps can be used to create dung beetle mammal networks. First network based on dung beetle molecular gut content analysis (60) beetle individuals from pitfall traps, and hand collections. These include successful amplification from 5 species of dung beetles, and 8 species of mammals from multiple feeding guilds. Our preliminary results suggest that common diurnal species foraged on dung from all primate species present in the area (howler, spider and capuchin monkeys) that are active during the day, whereas nocturnal Deltochilum sp. beetles included jaguar, margay and puma dung, as well as armadillos which are more night active mammals. Such dial partitioning contributes to overall network specialization (H2’ =0.42). In addition, to the importance of studying mammal dung beetle networks this method could improve upon standard methods for surveying mammal diversity, by requiring fewer man hours and better species coverage.