Composition-dependent & density-dependent seed removal rates in the harvester ant Messor barbarus

This study evaluated the effect of relative density and composition of locally-available seed species on selection criteria in the harvester ant M. barbarus. The study method was based on the use of cafeteria-style feeding experiments. Results suggest that this species tends to gather the most plentiful seeds, although selection may be modified by other factors such as seed mass. General bait composition, or "seed environment" also proved to be a major factor in selection: gathering-rates increased in the presence of strongly-preferred seeds, an increase observed even in the case of "rare" or low-density seeds. All this enables evaluation of the effect of this species on the plant community.