21-25 cm, sexes similar. This is the smallest of the terns, and has a very high rate of wing beats. It fishes with continuous hovering movements followed by dives. Present between May and August-September. It nests on bare or sparsely vegetated sandbanks and on some islets without vegetation within the valli. This is a species suffering conservation problems due to the intrusiveness of bathers, predation by rats and herring gulls, the flooding of nests and low availability of suitable sites.