The silver gull (''Chroicocephalus novaehollandiae'') is a gull in

Oceania Oceania ( , ) is a region, geographical region including Australasia, Melanesia, Micronesia, and Polynesia. Outside of the English-speaking world, Oceania is generally considered a continent, while Mainland Australia is regarded as its co ...

. It is the most common

gull Gulls, or colloquially seagulls, are seabirds of the subfamily Larinae. They are most closely related to terns and skimmers, distantly related to auks, and even more distantly related to waders. Until the 21st century, most gulls were placed ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. It has been found throughout the continent, but particularly at or near coastal areas. It is smaller than the

Pacific gull The Pacific gull (''Larus pacificus'') is a gull, native to the coasts of Australia. It is moderately common between Carnarvon, Western Australia, Carnarvon in the west, and Sydney in the east, although it has become scarce in some parts of the s ...

(''Larus pacificus''), which also lives in Australia. The silver gull should not be confused with the herring gull, which is called "silver gull" in many other languages (

scientific name In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

''Larus argentatus'', German , French , Dutch ), but is a much larger, robust gull with no overlap in range.

Taxonomy

It has traditionally been placed in the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

Larus ''Larus'' is a large genus of gulls with worldwide distribution (by far the greatest species diversity is in the Northern Hemisphere). Many of its species are abundant and well-known birds in their ranges. Until about 2005–2007, most gulls ...

'', as is the case with many gulls, but is now placed in the genus ''

Chroicocephalus ''Chroicocephalus'' is a genus of medium to relatively small gulls which were included in the genus ''Larus'' until genetic evidence published in 2005 showed that ''Larus'' as then constituted was paraphyly, paraphyletic. Ten species are currentl ...

''.

Hartlaub's gull Hartlaub's gull (''Chroicocephalus hartlaubii'') is a small gull in the genus ''Chroicocephalus''. It was formerly (as with other related gulls) placed in the genus ''Larus'' until genetic research demonstrated that the old broad view of that gen ...

(''C. hartlaubii'') of

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

was formerly sometimes considered to be

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

of the silver gull. There are three subspecies: * ''C. n. forsteri'' ( Mathews, 1912) – north and northeast Australia, New Caledonia,

Loyalty Islands Loyalty Islands Province (, ) is one of the three top-level administrative subdivisions of New Caledonia. It encompasses the Loyalty Islands () archipelago in the Pacific Ocean, located northeast of the New Caledonian mainland of Grande Terre. ...

* ''C. n. novaehollandiae'' ( Stephens, 1826) – southern Australia and Tasmania * ''C. n. scopulinus'' ( Forster, JR, 1844) or

red-billed gull The red-billed gull (''Chroicocephalus novaehollandiae scopulinus''), also known as tarāpunga and as the mackerel gull, is a native gull, seagull of New Zealand, being found throughout the country and on outlying islands including the Chatham I ...

– New Zealand

Description

Adult

The head, body, and tail of an adult silver gull are white, and the wings are light grey with white-spotted, black tips. Adults range from in length. Their wingspan ranges from . Adults have bright red beaks which gets brighter during breeding or when they get older.

Juvenile

Juveniles have brown patterns on their wings, and a dark beak.

Distribution and habitat

Silver gulls are found in all states of Australia, as well as

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

and

New Caledonia New Caledonia ( ; ) is a group of islands in the southwest Pacific Ocean, southwest of Vanuatu and east of Australia. Located from Metropolitan France, it forms a Overseas France#Sui generis collectivity, ''sui generis'' collectivity of t ...

. It is a common species near human habitations and beaches, having adapted well to urban environments and thriving around shopping centres and garbage dumps. Their successful adaption to urban habitats have seen their population increase in areas of human activity, with the availability of nesting grounds the only limiting factor on population growth. Silver gulls have twice been recorded in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

; one bird was shot in August 1947 at the mouth of the

Genesee River The Genesee River ( ) is a tributary of Lake Ontario flowing northward through the Twin Tiers of Pennsylvania and New York (state), New York in the United States. The river contains several waterfalls in New York at Letchworth State Park and Roch ...

Lake Ontario Lake Ontario is one of the five Great Lakes of North America. It is bounded on the north, west, and southwest by the Canadian province of Ontario, and on the south and east by the U.S. state of New York (state), New York. The Canada–United Sta ...

, and another was photographed in

Salem County, New Jersey Salem County is the westernmost county in the U.S. state of New Jersey. Its western boundary is formed by the Delaware River, and it has the eastern terminus of the Delaware Memorial Bridge, which connects the county with New Castle, Delaw ...

, in autumn 1996. Both are believed to have escaped from captivity.

American Ornithologists' Union The American Ornithological Society (AOS) is an ornithological organization based in the United States. The society was formed in October 2016 by the merger of the American Ornithologists' Union (AOU) and the Cooper Ornithological Society. Its ...

(2000): Forty-second supplement to the American Ornithologists' Union Check-list of North American Birds. ''

Auk Auks or alcids are birds of the family Alcidae in the order Charadriiformes. The alcid family includes the Uria, murres, guillemots, Aethia, auklets, puffins, and Brachyramphus, murrelets. The family contains 25 extant or recently extinct speci ...

'' 117(3): 847–858. DOI: 10.1642/0004-8038(2000)117 847:FSSTTA.0.CO;2.

Behaviour

The silver gull has a sharp voice consisting of a variety of calls. The most common call is a harsh, high pitched 'kwarwh'.

Feeding

The silver gull naturally feeds on worms, fish, insects and crustaceans. It is a successful scavenger, allowing increased numbers near human settlements. It is known to pester humans for scraps and steal unattended food.

Breeding

Breeding occurs from August to December, typically in large colonies on offshore islands. The nest is located on the ground and consists of seaweed, roots, and plant stems. The nests may be found in low shrubs, rocks and jetties. Typical clutch size is one to three eggs. Often two broods are raised in a year, and both adults share nest-building, incubation and feeding.

Gallery

File:Silver gull scream.webm, A silver gull performs its distinctive screaming call. File:Chroicocephalus novaehollandiae scopulinus.jpg , Foraging by oscillating its foot in sand at low tide to uncover prey File:Silver gull-03.JPG, Egg and nestlings in nest at Phillip Island Nature Park, Victoria File:Chroicocephalus novaehollandiae MHNT.ZOO.2010.11.125.20.jpg, Eggs - MHNT File:Silver Gull in flight.jpg, Immature in flight File:Chroicocephalus novaehollandiae - Silver Gull - Bathing.jpg, Bathing File:Silver Gull flight.ogv, In flight, near Gold Coast, Australia File:Chroicocephalus novaehollandiae - Green Island.jpg, Mature adult on the pier of Green Island east of Cairns File:Silver Gull JCB.jpg, On Michaelmas Cay, Great Barrier Reef, Queensland, Australia