Connell’s field experiment on barnacles illustrated the phenomenon of

Competitive release is a phenomenon in which the distributional range of a species expands when the competing species is removed. The distribution of the species is restricted to a small geographical area in the presence of a competitively superior species. Connell’s elegant field experiments showed that on the rocky seacoasts of Scotland, the larger and competitively superior barnacle Balanus dominates the intertidal area and excludes the smaller barnacle Chthamalus from that zone.