Sabine S. Nooten, Kin H. Chan, Patrick Schultheiss, Taylor A. Bogar and Benoit Guénard
This is a plain language summary of a Functional Ecology research article which is published here.

Rapid and selective loss of biodiversity, with a disproportionate loss of large species, has deep impacts on ecological processes, and prompted considerable interest in linking functional traits with ecological processes. Body size is a key trait in organisms that is linked to multiple life history features and influences vital ecological functions. Human induced disturbances, such as climate and land use changes and species invasions, have a greater impact on larger species than on smaller ones. These lead to diminished key ecosystem services, like seed dispersal, pollination, and decomposition. Decomposition of dead organic matter is essential for nutrient cycling in the environment and is performed by a wide range of organisms. Dead animal matter – carrion – is a temporary protein-rich food source that is quickly consumed by a range of scavenging and predatory insects, including flies and ants. Such decomposer communities are essential, as they contribute to limiting the spread of diseases and pathogens. In this study, we use carrion of a small mammal (mouse) to investigate how body size influences the role of ants in decomposer communities. Our results show the crucial role of ants during the decomposition process and highlight the differential roles of ants in function of their body size. Indeed, large ants show a double action by increasing decomposition rate and predating on maggots while small ants are rather inefficient decomposers and don’t act as predators on other decomposer species. We show that differentiating key taxonomic groups as a function of their body size is key to untangling the diversity and variety of roles they play within complex ecological processes.