Use of a generalised linear model to test habitat preferences: the example of Zingel asper, an endemic endangered percid of the River Rhône

SUMMARY 1. A study of microhabitat preferences was conducted on Zingel asper, an endangered endemic species from the Rhône catchment. A generalised linear model allowed us to test statistically the non‐random habitat selection and the effect of season and site on this habitat selection. 2. The analysis detected significant preferences for the three physical variables considered: water depth, water velocity and substratum size. 3. A seasonal shift in the substratum size preference was found: preference for stones increasing during the spawning season. Depth preference varied between sites, suggesting a possible plasticity in habitat selection. 4. These results suggest that the availability of suitable physical habitat plays a significant role in determining fish distribution in the River Beaume.