Large bird (about 56 cm or 22 in) with a wide wingspan (about 140 cm or 4.5 ft), with the appearance of a tern and similar in size to a seagull. Broad, long and red bill with a dark tip. White plumage except in back and wings, which are grey, and a black cap on the head. The legs are black, the wings are pointed and the tail is forked.
Wintering species in the Gulf of Cádiz and in migratory passage across the Mediterranean. It breeds in the Baltic, in coastal areas or large lakes. During the winter it is a coastal species.
Bird that is observed in the province during its migratory passage. It breeds from April and in mixed colonies with gulls and terns. Nest on the ground. One laying of 2 eggs. It feeds on medium sized fish caught in groups and by means of the plunging technique. It also consumes carrion, eggs and chicks of other birds.
Uncommon species in Malaga that can be watched occasionally at the mouth of the Guadalhorce.
The species was described by the zoologist Peter Simon Pallas in the Caspian Sea. "Hydroprogne" literally means "aquatic swallow" (from Greek, "procne"), so its name refers to a typical sea swallow of the Caspian. Procne was the daughter of the king Pandion of Athens, turned into a swallow by the gods after the revenge that she took for the infidelity of her husband: she killed and served cooked the son of her unfaithful spouse.