Medium-sized bird (approx 41 cm or 16 in) with pale grey upperparts and white underparts. Long, pointed bill of black colour with a whitish or yellowish tip. Black legs. It has a black cap on its head that sometimes forms a small crest. In winter the cap is reduced to the nape of the neck and becomes whiter. In flight there is a white silhouette with long, pointed wings, with a long and forked tail.
Coastal areas of warm waters. To breed, it forms colonies in beach, dune or marsh areas with close access to the coast.
Wintering species in Malaga that can also be observed in migratory passage. It breeds in large colonies in northern Europe. Nests on the ground. One annual laying from April of 1 to 2 eggs. It feeds mainly on fish, also capturing shrimp, crustaceans, snails, worms, and small insects on dry land. It is an unerring fisherman with a similar technique to gannets. It plunges, even when the sea is steep, reaching up to 15 meters diving if necessary.
It can be watched along the entire coast of Malaga, entering the lagoons of the mouth of the Guadalhorce and Vélez rivers.
Terns are popularly known as "sea swallows". Their stylized silhouette and forked tail, along with their frequent plunge dives, are typical of many ports and beaches in Malaga in winter.