A black seabird with metallic green sheen, present year-round along the rocky coasts of the Sinis and around Mal di Ventre Island. The Mediterranean subspecies desmarestii is endemic to the Mediterranean and has a small population, of which Sardinia hosts a significant share at national level.
It nests in crevices and ledges of the cliffs between January and May, when colonies are particularly sensitive to disturbance. It feeds by diving to depths of over 30 metres, mostly over sandy seabeds and Posidonia meadows. Approaching breeding sites by boat during the nesting season is the main cause of nest abandonment.