Introduced dung beetles suppress methane emissions from cattle dung and alter the temporal dynamics of greenhouse gas flux

Livestock agriculture is a primary driver of anthropogenic greenhouse gas (GHG) emissions, with cattle dung acting as a significant source of carbon dioxide (CO ₂ ), methane (CH ₄ ) and nitrous oxide (N ₂ O). Dung beetles (Coleoptera: Scarabaeidae) are critical ecosystem service providers that modify dung structure, yet their influence on specific GHG fluxes remains variable across different climatic regions and beetle assemblages. In Australia, where introduced beetle species are active year‐round, their potential for GHG mitigation is poorly quantified.

We investigated the impact of dung beetle activity on GHG (total, CO ₂ , N ₂ O and CH ₄ ) and ammonia (NH ₃ ) fluxes from cattle dung. Using 90‐day chamber mesocosms, we compared emission profiles between pats colonised by a field‐representative mix of four species ( Euoniticellus intermedius , E. africanus , E. fulvus and Onthophagus granulatus ) and beetle‐free controls. Cumulative CH ₄ flux was 85% lower in beetle treatments compared to controls. Control pats exhibited distinct CH ₄ flux peaks at Day 6 and Day 16, whereas beetle‐colonised pats maintained near‐zero fluxes throughout the experiment. Conversely, beetles accelerated initial CO ₂ release, causing an earlier flux peak within the first 14 days compared to controls. Total greenhouse gas flux was nearly 18% lower when beetles were present.

These findings indicate that dung beetle activity is associated with altered greenhouse gas flux patterns in cattle dung. The presence of active beetle populations suggests an inherent ecosystem service that may reduce the net methane footprint of grazing systems. Our study highlights the importance of considering invertebrate‐mediated processes in agricultural greenhouse gas assessments.