Pacific Gull Larus pacificus Scientific name definitions

58–65 cm; 900–1185 g; wingspan 137–157 cm. White head and underbody , with blackish mantle and wings, the latter with white trailing edge but lacking white windows on primaries; tail  white with narrow black subterminal band; bill very deep and heavy (the heaviest of any gull), yellow, broadly tipped red ; nostrils oval rather than slit-like; legs and feet yellow.  Larger than the Kelp Gull L. domi­nicanus, from which it differs also in its darker mantle, presence of a  black tail band and a much heavier bill. The juvenile  is mottled dark brown ; the bill is glossy black. The first-year plumage is still very dark but with a pale face; the bill base is pinkish. Second-year  birds have dark brown wings, a whitish mottled body, paler rump and a black-tipped yellow bill. Older immatures are progressively paler but the full adult plumage is not acquired until the fifth year (1 Pizzey, G., Knight, F. and Menkhorst, P. eds. (2007). The Field Guide to the Birds of Australia. 8th edition. Harper Collins, Pymble, New South Wales. Close ).The two races differ minimally: the eastern form (race pacificus) has a white eye and a complete red tip to the bill and the western form (race gergii) has a red eye and an incomplete red tip to the bill.

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Editor's Note: Additional distribution information for this taxon can be found in the 'Subspecies' article above. In the future we will develop a range-wide distribution article.

Coastal ; seldom occurs far inland but it is occasionally seen on farmland and rubbish tips near the coast and may travel a short way up rivers.  It selects sandy, or less often, rocky coasts and sandy beaches. In eastern Australia it frequents areas, such as estuaries, bays and harbours, that are protected from ocean swells. In Western Australia, it occurs occasionally in harbours but mostly on exposed coasts and offshore islands. It usually avoids human habitation but is occasionally seen on farmland and rubbish tips near the coast. It can be found roosting or loafing in elevated situations such as rocky headlands or on structures such as wharves and jetties (1 Pizzey, G., Knight, F. and Menkhorst, P. eds. (2007). The Field Guide to the Birds of Australia. 8th edition. Harper Collins, Pymble, New South Wales. Close ). It breeds on elevated offshore islands; more rarely on headlands in the southeast of its range.

Most populations relatively sedentary, but young disperse up to 200 km. Post-breeding movement occurs from Tasmania, N to Victoria and New South Wales coasts, uncommonly as far as Queensland. Accidental in interior and N Australia. Vagrant to New Zealand, where an immature bird was at Dargaville Beach, North Island, in January 2010.

Fish, squid, and intertidal molluscs, echinoderms and crabs  ; fish offal  , carrion  and refuse; eats many gastropods (Turbo undulatus) (2 Barker, R. D., and W. J. M. Vestjens (1989). The Food of Australian Birds. Volume 1: Non-passerines. CSIRO, Melbourne, Australia. Close ). Pellet analyses at a colony on Green Island, Tasmania, found that the principal prey there was mainly crabs (Ovalipes australiensis, Paragrapsus gaimardii) and chitons, as well as fish waste (3 Coulson, R. and Coulson, G. (1993). Diets of the Pacific Gull Larus pacificus and Kelp Gull Larus dominicanus in Tasmania. Emu. 93(1): 50–53. Close ). Takes bird eggs and young, and occasionally adult birds, e.g. White-faced Storm-petrel (Pelagodroma marina). Feeds  by walking along beaches  and intertidal zone, and also by plunge-diving. May open gastropods by dropping them on rocks or on other hard surfaces.

Gives a shouted “ow-ow” which can be quite long. Also a short “oh oh”, throaty “cark-cark” or “auk-auk” as well as gruff chuckles and whining stutters (1 Pizzey, G., Knight, F. and Menkhorst, P. eds. (2007). The Field Guide to the Birds of Australia. 8th edition. Harper Collins, Pymble, New South Wales. Close ). 

September–January. Breeds as scattered single pairs or in small, loose colonies on high points on headlands or islands. A colony of 400 pairs has been reported at Wilson's Point, S Victoria. The nest may be no more than a scrape in the ground but others comprise a neatly constructed shallow bowl of sticks, grass, seaweed or feathers. Both sexes build the nest with the female doing most of the incubation while the male forages for food and stands guard near the nest. The clutch is 3 eggs (1–3); incubation  23–26 days. 

Not globally threatened (Least Concern). Although not at serious risk it is nowhere common. About 100 breeding colonies known, but the total population is probably does not reach 10,000 pairs. Population estimates in 1999 suggested that race pacificus numbered 4950 individuals and race georgii 6000 individuals (4 Wetlands International (2015). Waterbird Population Estimates. Wetlands International, Wageningen, The Netherlands. Close ). The breeding range of race pacificus expanded during the early 20th century, when it bred as far north on the Pacific Coast as S Queensland; it has has since contracted southwards, perhaps reflecting competition there with the recently established and rapidly increasing population of the Kelp Gull L. dominicanus. The breeding range of race georgii has more recently expanded northwards along the western Australian coast.  In Tasmania, populations have been culled to protect other seabirds.