 For instance, McGeoch and Gaston (2002) show that the number of satellite (rare) species declines with the increase of sampling grains, but the number of core (common) species increases, showing a tendency from a bimodal OFD towards a right-skewed unimodal distribution.This is because species range, measured as occupancy, is strongly affected by the spatial scale and its aggregation structure, known often as the scaling pattern of occupancy.Such scale dependence of occupancy has a profound effect on other macroecological patterns, such as the occupancy-abundance relationship.