The Bembridge marls, freshwater, estuarine and marine clays and marls (70–120 ft.) rest upon the Bembridge limestone, a freshwater pool deposit (15–25 ft.), with large land snails (Amphidromus and Helix), freshwater snails (Planorbis, Lymnaea), and the fruits of Chara.
The prey of Red-crowned Barbet include land snails of the genus Amphidromus.