The spatial scale at which landscape structure best predicts an ecological response (the ‘scale of effect’) requires measuring landscape structure at multiple spatial extents. The scale of effect is often determined by a species’ mobility, but reproductive potential may also influence the scale of effect. I tested these hypotheses using body length, relative wing size, and egg count measurements of carabid beetles, proxies for movement, dispersal, and reproductive potential, respectively. I determined the scale of effect for 13 carabid species, and calculated cross-species correlations
between the scale of effect and body length, relative wing size, and mean eggs. I found a positive correlation between body length and the scale of effect, and negative correlations between relative wing size and mean egg counts and the scale of effect. Surprisingly, model ranking revealed mean egg counts to be the best predictor of the scale of effect followed by body length.