Microhabitat use, movements and abundance of gilt darters (Percina evides) in southern Appalachian (USA) streams

Abstract –  We examined microhabitat use by gilt darters ( Percina evides ) in two streams in the south-eastern USA. Darters were over-represented in erosional microhabitats with higher average velocities and more cobble. Male darters tended to show stronger selection than females. Size-based analyses showed that larger (≥60 mm) gilt darters tended to use microhabitats with more heterogeneous substrata and more boulder than smaller (≤59 mm) darters. We also conducted a short-term movement study and calculated population estimates based on mark–recapture data in autumn 2005. Darters moved both long and short distances with 40% of all recaptures occurring within 5 m of the initial capture point. Using Program mark and model-averaged parameter estimates gilt darter density was 0.31 darters·m⁻² (225 darters/730 m²). Conservation of this species will require the preservation of erosional habitats in streams.