The effect of fly exclusion on scavenger community and carrion decomposition varies with carrion type in a Tibetan alpine meadow

Abstract

Animal carrion, an ephemeral but nutritional resource, supports diverse invertebrate species involved in the decomposition process. Necrophagous flies, as the primary colonisers on carrion, can largely affect the invertebrate community and associated carrion decomposition rates; however, field data integrating different carrion types to examine the effect of fly exclusion are evidently lacking. We conducted a field experiment to investigate the responses of arthropod scavengers and the carrion decomposition rate to fly exclusion using yak carrion and chicken carrion in a Tibetan alpine meadow. Results show that flies (maggots) and necrophagous beetles (Coleoptera: Silphidae) were the predominant scavengers on both yak carrion and chicken carrion in the Tibetan alpine meadow. The responses of maggots, necrophagous beetles and predatory beetles varied with carrion types. Specifically, during the early stage of decomposition, maggots were more abundant on chicken carrion compared to yak carrion, while necrophagous beetles and predatory beetles dominated yak carrion during the late stage. The exclusion of flies significantly decreased the richness and the abundance of arthropods on yak carrion, as well as the decomposition rate of yak carrion. Fly exclusion significantly decreased the abundance of arthropods on chicken carrion but not affected the decomposition rate of chicken carrion. Our findings clearly demonstrate that excluding flies can modify temporal successional traits and structure of scavenger community, as well as decomposition rates of both chicken carrion and yak carrion, albeit with varying effect degrees. This study represents a comprehensive investigation into the influences of necrophagous flies and carrion type on carrion decomposition on the Tibetan Plateau, which holds important implications for understanding necrophilous assemblages.