The Gull research in the Bailiwick of Guernsey focuses on the three species breeding in the Islands (Great Black-backed Gull Larus marinus, Herring Gull Larus argentatus and Lesser Black-backed Gull Larus fuscus). The Bailiwick of Guernsey consists of the Channel Islands of Guernsey, Alderney, Sark, Herm and Jethou (with associated rocks and islets). All three projects are gathering data to assess aspects of the breeding and migratory ecology of these gull species. Although Black-headed Gulls (Chroicocephalus ridibundus) do not nest in the Channel Islands, a small number are being colour-ringed to discover more about the origins of our wintering birds.

Similar projects are now also being run on Great Cormorants (Phalacrocorax carbo) nesting in the Islands, and Common Moorhens (Gallinula chloropus) nesting and wintering here.