Trait-similarity and trait-hierarchy jointly determine fine-scale spatial associations of resident and invasive ant species

Interspecific competition, a dominant process structuring ecological communities, is influenced by species' phenotypic differences. Limiting similarity theory holds that species with similar traits should compete intensely (\"trait-similarity\"). In contrast, competing theories including modern coexistence theory emphasize that species with traits conferring competitive advantages should outcompete others (\"trait-hierarchy\"). Either or both of these mechanisms may drive competitive exclusion, but their relative importance and interacting effects are rarely studied. Here, we explore empirically whether trait-similarity and trait-hierarchy can explain fine-scale spatial associations observed between invasive and native ant species in a tropical assemblage. We find that pairwise co-occurrences between the invasive red imported fire ant Solenopsis invicta and 28 other species across relatively homogenous grasslands can be explained largely by an interaction of trait-similarity and trait-hiera...