One of these i expect
Pacific gull, Larus pacificus
Belcher’s gull, Larus belcheri
Olrog’s gull, Larus atlanticus
Black-tailed gull, Larus crassirostris
Heermann’s gull, Larus heermanni
Common gull or mew gull, Larus canus
Short-billed gull, Larus brachyrhynchus
Ring-billed gull, Larus delawarensis
California gull, Larus californicus
Great black-backed gull, Larus marinus
Kelp gull, Larus dominicanus (called “southern black-backed gull” or “karoro” in New Zealand)
Cape gull, Larus dominicanus vetula
Glaucous-winged gull, Larus glaucescens
Western gull, Larus occidentalis
Yellow-footed gull, Larus livens
Glaucous gull, Larus hyperboreus
Iceland gull, Larus glaucoides
Kumlien’s gull, Larus glaucoides kumlieni
Thayer’s gull, Larus glaucoides thayeri
European herring gull, Larus argentatus
American herring gull, Larus smithsonianus
Caspian gull, Larus cachinnans
Yellow-legged gull, Larus michahellis
East Siberian herring gull, Larus vegae
Armenian gull, Larus armenicus
Slaty-backed gull, Larus schistisagus
Lesser black-backed gull, Larus fuscus
Heuglin’s gull, Larus fuscus heuglini