AUTHORS: Sarah Walker, Michigan State University; Brian Roth, Michigan State University; William Ota, Michigan State University; Colin Assenmacher, Michigan State University; Aaron Sullivan, Michigan State University
ABSTRACT: Red swamp crayfish (Procambarus clarkii) are global invaders that negatively affect ecosystems worldwide through bank erosion, trophic interactions, and competition. There is limited research about their habitat preferences in invaded areas inside North America or in lentic ecosystems. Our study evaluates habitat selectivity by red swamp crayfish in southeastern Michigan ponds where red swamp crayfish were first found in 2017. We used radio telemetry to track the movement and habitat characteristics of confirmed locations for 46 crayfish at 4 sites in June through September of 2022. We used remotely sensed habitat characteristics from 2022 NAIP aerial imagery and determined macrophyte cover, terrestrial vegetation cover, and shore use of each detection. We then analyzed these classifications for selectivity using Ivlev’s Electivity Index. We gave further context to these classifications and selectivity by analyzing them with our field habitat observations in a logistic regression. Our index indicated a strong avoidance of shore areas, an avoidance of no cover areas, and a non-selective use of macrophyte areas. We also demonstrated slightly more selectivity for areas with terrestrial cover in male I crayfish and less avoidance of terrestrial vegetation cover areas in ponds with less macrophytes. Field observed deep water habitat characteristics significantly (p-value
