Multispecies Niche Overlap: Moving Beyond Pairwise Metrics to Understand Community-Wide Similarities in Resource Use

Measures of niche overlap-particularly in terms of resource use-are important tools in a wide range of ecological and evolutionary studies. A variety of these overlap indices are used, but all are pairwise measures. Yet, most communities are more complex, suggesting the potential value of measures that can be extended to the simultaneous overlap among more than two species. Here we extend percent overlap to any number of potentially overlapping species and then partition the amount of overlap attributable to any specific subset of species. We then apply this partitioned multispecies percent overlap metric to both simulated and empirical communities. Additionally, we provide recommendations on the use and extension of this metric for a variety of research goals across topics in both ecology and evolution, illustrating how this methodology may capture interactions and structures of niche space in ways that traditional, pairwise metrics overlook. Such potential insights include identifying foraging guilds, measuring the degree of diffuse competition, and providing overall niche overlaps within and across phylogenetic clades.