Proportion of individuals found at each location (two and four meter upstream (us) and downstream (ds) and at the beaver slide) relative to the total mussels sampled per beaver slide. Different shapes indicate the stream (circle = Goldbach, square = Schinderbach, diamond = Ischler Achen, triangle = Scharlach), while the shading represents lateral distance from the stream bank (black = directly at the bank, grey = 50 cm into the stream, white = 1 m into the stream; see Fig. 2). Points are jittered slightly for clarity.