Conservation at the nexus of niches: Multidimensional niche modeling to improve management of Prairie Chub.

The article focuses on delineating the spatial distribution of Prairie Chub (Macrhybopsis australis), a regionally endemic freshwater fish under consideration for Endangered Species Act listing, using the BAM ecological niche framework that integrates abiotic (A), biotic (B), and movement (M) factors. Employing random forest modeling with environmental variables, hybridization data with Shoal Chub (M. hyostoma), and mark–recapture movement data, the study found that the realized niche of Prairie Chub spans approximately 645 km of river in the upper–middle Red River basin, primarily in medium to large rivers with high habitat connectivity. Inclusion of movement data significantly improved model predictions, highlighting the species' capacity for long-distance dispersal, while incorporation of biotic interactions (hybridization zone) did not enhance model accuracy. The findings suggest that maintaining longitudinal habitat connectivity and preventing further fragmentation are critical for conserving Prairie Chub, with potential range expansion achievable through restoration of fluvial connectivity.