Effect of Digitonthophagus gazella on taxonomic diversity and functional traits of native dung beetles in Brazilian introduced pastures

Abstract Invasive species can alter ecosystem processes, disrupt food webs, and cause significant economic and health-related impacts. Digitonthophagus gazella , an African dung beetle introduced globally for pasture improvement, exemplifies the ecological risks of biological invasions. In South America, its assisted introduction and subsequent invasion led to significant declines, with some species becoming locally extinct. We aimed to investigate how the abundance (total, females, and males) and morphological traits (body size and horn size) of D. gazella relate to native dung beetle assemblage metrics, including abundance and species richness of the overall assemblage and functional groups. Additionally, we examined how both D. gazella and native dung beetle variables respond to fine-scale climatic conditions in Brazilian pastures where the species has been introduced. Sampling took place over 52 weeks (April 2020–March 2021) in the Cerrado–Pantanal transition zone in Aquidauana, midwestern Brazil, covering both dry and rainy seasons. Our results indicate that the presence of D. gazella was not associated with changes in the overall temporal distribution of native dung beetles, but it was associated with lower abundance of endocoprid species. Native dung beetle abundance increased with temperature, while humidity reduced the total abundance of D. gazella and its females. Temperature also had a positive effect on D. gazella males. Overall, climatic factors were more influential than the presence of D. gazella in driving trait-based filtering of native species over time. The D. gazella case highlights how invasive species can restructure native assemblages, outcompete similar species, and potentially alter ecosystem functions like dung removal and nutrient cycling.