Fevziye Hasan, Louis A Schipper, Kiri Joy Wallace, Simon V Fowler, Andrew D Barnes

Dung beetles are known to carry out a range of ecosystem functions such as secondary seed dispersal, bioturbation, nutrient cycling, plant growth, pest and parasite control, and trophic regulation, many of which support key ecosystem services. Despite the globally purported significance of this group of insects for ecosystem functioning, there has been no quantitative synthesis to establish the extent of dung beetle effects on ecosystem functions at global, regional, and habitat scales. To address this knowledge gap, we conducted a meta-analysis using 455 effect sizes collected from 66 published studies. The analyses evaluated the overall effects of dung beetles on 24 ecosystem functions, with additional subgroup analyses investigating (i) variation in dung beetle nesting behaviour, (ii) ecosystem type, and (iii) study methodology. Trophic regulation was found to be the ecosystem function most strongly enhanced by dung beetles, followed by nutrient cycling, plant growth enhancement, dung removal, bioturbation, and secondary seed dispersal. However, our analysis revealed considerable biases across the type of function assessed, with a significant focus on dung removal (57% of measured ecosystem functions) compared to nutrient cycling (20%) and less focus on other processes such as bioturbation, secondary seed dispersal, plant growth enhancement, and trophic regulation (<10%). our findings confirm that dung beetles have a net positive effect on multiple ecosystem functions, but with uneven distribution in the measurement of these functions across countries and latitudes, which could potentially lead to biased estimates of the impact of dung beetles on ecosystem functioning. These results emphasize the importance of quantifying a range of ecosystem functions beyond just dung removal, so as to gain a better understanding of the effects of dung beetles on multiple ecosystem services. By explicitly measuring multiple ecosystem functions, future ecological research on dung beetles will better describe the global contributions of dung beetle biodiversity to ecosystems and people.