Settlement and population increase of the Mediterranean Gull <i>Larus melanocephalus</i>, breeding in the northwestern Adriatic coastal wetlands. A thirty-year study

This note aims to provide an analytical description of the colonization of the coastal areas in northeastern Italy by the Mediterranean Gull (Larus melanocephalus) and of the increase in its breeding population from 1995 to 2024, using both unpublished data and published information. After the first nesting of a single pair in 1996, the species nested occasionally until 2003, then increased to 5601 pairs in 2024. The wetlands of the northwestern Adriatic coast host significant numbers of breeding Mediterranean Gulls, probably one of the largest populations in Europe. Breeding occurred both on saltmarsh islets within lagoons regularly flooded by high tides and inside fish farms where water levels are strictly regulated. Recently, fish farms hosted 70-100% of the breeders, thus playing a key role in the species’ conservation. Climate change, and in particular the increase of floods and storms during the breeding season, is expected to induce the disappearance of the colonies outside fish farms.