Individual asymmetric competition responses across multidimensional niches may enable coexistence of closely related species

Abstract

Many studies have focussed on niche differentiation at the population level to explain the coexistence of similar species. However, information on how individual-level processes across multidimensional niches shape community dynamics and species coexistence, especially for nocturnal, small and highly mobile animals, is limited. In this study, we employed a combination of metabarcoding and GPS tracking technologies to investigate the coexistence mechanisms between two sympatric bat species, Hipposideros armiger and H. pratti, by analysing individual niche responses to competition across temporal, spatial and dietary dimensions. Results showed that (1) traditional population-level analysis revealed no significant niche partitioning along single dimensions. However, (2) individual-level analyses uncovered sophisticated coexistence mechanisms through asymmetry responses to interspecific competition via temporal and dietary dimensions within limited habitat ranges. (3) This asymmetry response ensures stability of complementary relationships through coordinated interactions across three dimensions. (4) Intraspecific competition contributes to species asymmetry stabilization by modifying temporal activity patterns of both species, thereby reducing interspecific competition and facilitating coexistence. In conclusion, H. armiger and H. pratti achieved stable coexistence through coordinated responses across all three niche dimensions, with individuals demonstrating complementary patterns between dietary utilization and temporal activity, rather than single-dimensional partitioning. Our work provides a comprehensive framework for understanding how individual-level multidimensional niche adjustments and asymmetric competitive responses facilitate stable coexistence in sympatric species. Read the free Plain Language Summary for this article on the Journal blog.