View source for Red-billed gull

{{Short description|Subspecies of bird, native of New Zealand}}
{{Use New Zealand English|date=April 2013}}
{{subspeciesbox
| name = Red-billed gull
| image = Chroicocephalus novaehollandiae scopulinus, Kaikōura, New Zealand 08.jpg
| image_caption = An adult gull in [[Kaikōura]], New Zealand
| image2 =Red-billed gulls calling, Otago Peninsula, NZ.ogg
| status2 = D
| status2_system = NZTCS
| status2_ref = <ref name=NZTCS>{{Cite web|url= https://nztcs.org.nz/nztcs-species/11165|title= Larus novaehollandiae scopulinus|website=nztcs.org.nz|access-date=2022-09-14}}</ref>
| genus = Chroicocephalus
| species = novaehollandiae
| species_link = Silver gull
| subspecies = scopulinus
| authority = ([[Johann Reinhold Forster|Forster]],  1844{{efn| Published posthumously in [https://www.biodiversitylibrary.org/item/129805#page/128/mode/1up ''Descriptiones animalium'', p. 106]}})
| synonyms =
''Larus novaehollandiae scopulinus'',
''Larus scopulinus''
}}

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 Islands]] and [[subantarctic]] islands. It was formerly considered a separate species but is now usually treated as a [[subspecies]] of the [[silver gull]] (''Chroicocephalus novaehollandiae'').<ref name=ioc>{{cite web| editor1-last=Gill | editor1-first=Frank | editor1-link=Frank Gill (ornithologist) | editor2-last=Donsker | editor2-first=David | year=2019 | title=Noddies, gulls, terns, auks | work=World Bird List Version 9.2 | url=https://www.worldbirdnames.org/bow/gulls/ | publisher=International Ornithologists' Union | access-date=24 June 2019 }}</ref><ref name=hbw>{{cite book | last1=Burger | first1=J. | last2=Gochfeld | first2=M. | last3=Kirwan | first3=G.M. | last4=Garcia | first4=E.F.J. | chapter=Silver Gull (''Larus novaehollandiae'') | editor1-last=del Hoyo | editor1-first=J. | editor2-last=Elliott | editor2-first=A. | editor3-last=Sargatal | editor3-first=J. | editor4-last=Christie | editor4-first=D.A. | editor5-last=de Juana | editor5-first=E. | title=Handbook of the Birds of the World Alive | publisher=Lynx Edicions | doi=10.2173/bow.silgul2.01 | s2cid=241433727 | chapter-url=http://www.hbw.com/node/53991 | access-date=21 April 2017 }}</ref>

The [[Māori language|Māori]] name of this species is '''{{Lang|mi|tarāpunga}}''' or '''{{Lang|mi|akiaki}}'''.<ref>{{cite book|author=Barrie Heather|author2=Hugh Robertson|name-list-style=amp|title=The Field Guide to the Birds of New Zealand|edition=revised|publisher=Viking|year=2005}}</ref> Its vernacular name is sometimes also used for the [[dolphin gull]], a somewhat similar-looking but unrelated species that is found in coastal [[southern Chile]], [[Argentina]] and the [[Falkland Islands]].<ref>{{Cite web|url=http://datazone.birdlife.org/species/factsheet/Dolphin-Gull|title=Dolphin Gull (Larus scoresbii) - BirdLife species factsheet|website=datazone.birdlife.org|access-date=2019-03-22}}</ref>  As is the case with many gulls, the red-billed gull has traditionally been placed in the [[genus]] ''[[Larus]]''.

A national survey of breeding red-billed gulls carried out in 2014–2016 recorded 27,831 pairs nesting in New Zealand. The authors of the study based on the survey and published in 2018 said that the accuracy of previous estimates was questionable, but that the species nevertheless appeared to have declined nationally since the mid-1960s. The study also discussed the possible reasons for the decline and made a proposal for future monitoring.<ref>{{Cite journal|last1=Taylor|first1=Graeme A.|last2=Frost|first2=Peter G.H.|date=2018|title=The status of the red-billed gull (Larus novaehollandiae scopulinus) in New Zealand, 2014–2016|url=https://www.osnz.org.nz/sites/osnz.org.nz/files/FrostTaylor_Red-billed%20gull%20NZ_Notornis%202018.pdf|journal=Notornis|publisher=Birds New Zealand|volume=65|pages=1–13|access-date=2019-03-22|archive-date=2019-02-01|archive-url=https://web.archive.org/web/20190201091229/https://www.osnz.org.nz/sites/osnz.org.nz/files/FrostTaylor_Red-billed%20gull%20NZ_Notornis%202018.pdf|url-status=dead}}</ref>

==Description==
The red-billed gull is a fairly small [[gull]] with an all-red bill, red eye ring, red legs and feet, pale grey wings with black wingtips. The rest of the body and tail are white. There is virtually no [[sexual dimorphism|visual difference between the male and female birds]]. Juvenile gulls have a dark brown bill with only hints of red, making them difficult to distinguish from the [[black-billed gull]]. The legs are also brown and there are brown spots on the grey wings.

==Distribution==
It is the smallest gull commonly seen in New Zealand. The population is estimated at 500,000.{{Citation needed|date=March 2020|reason=If true, how come 444,000 are unpaired?}} It was formerly considered a distinctive species,<ref>{{cite book|author=Shirihai, H.|year=2002|title=A complete guide to Antarctic wildlife|publisher= Alula Press, Oy, Finland}}</ref> but looks similar to the [[silver gull]] found in [[Australia]], and is now considered to be a [[subspecies]].

==Behaviour==
[[File:Red billed gull eating berries 02.jpg|thumb|left|Eating [[Coprosma repens|taupata]] berries]]
Behaviourally, the red-billed gull is a typical gull. It is an aggressive [[scavenger]] and [[kleptoparasitism|kleptoparasite]]. Since European settlement its numbers have increased, especially around coastal towns and cities where it can scavenge from urban waste. It normally feeds on small fish, shell fish and worms (from pastures), and sometimes berries, lizards and insects. It's been reported to engage in [[worm charming]] in order to bring worms to the surface.<ref name="ESPN">{{Cite web |date=2007-03-20 |first=Keith |last=Sutton|title=Fiddling for worms |url=https://www.espn.com/outdoors/fishing/columns/story?columnist=sutton_keith&page=g_col_Sutton_fiddling_for_worms |access-date=2023-10-17 |website=[[ESPN]] |language=en}}</ref>

[[File:Chroicocephalus novaehollandiae scopulinus.jpg |thumb|right|Foraging by oscillating its foot in sand at low tide to uncover prey]]

==Life cycle==
They nest from October to December in colonies on the coast, either on islands or rocky headlands, cliffs and beaches. The birds form [[pair bond]]s which endure across seasons, but there is a certain amount of [[extra-pair copulation]]. [[Courtship feeding]] is an important part of the preparation for mating. Nests are well formed and may be constructed of seaweed, grasses, leaves and ice plants. Generally two to three eggs are laid, their colour ranges from brown to grey with light and dark brown spots all over. The bird generally lives up to 12 years, although individuals have also been found living up to 30 years.<ref>{{Cite news|title = Ex-pat Kiwi returns from US to study red-billed seagulls|url = http://www.stuff.co.nz/marlborough-express/news/kaikoura/3187352/Ex-pat-Kiwi-returns-from-US-to-study-red-billed-seagulls|newspaper = [[Stuff.co.nz]]|date = Dec 23, 2009|access-date = 2015-06-21|first = Emma|last = Dangerfield}}</ref>

== Gallery ==
<gallery mode="packed" heights="140" caption="Red-billed gull">
File:Red-billed gull portrait, New Brighton, New Zealand 03.jpg|Upper body
File:Chroicocephalus scopulinus LC0381.jpg|Adult with chick
File:Red-billed Gull in flight.jpg|Red-billed gull in flight
File:A balletic Looking Red Billed Gull.jpg|Landing
File:Red billed gull-07.jpg|Crouching
File:NeuseelandSeagulls.jpg|Second-winter, first-winter, and adult birds (first three, from front)
File:Red-billed gull (J).jpg|Juvenile bathing, [[Picton, New Zealand]]
File:Red-Billed Gull-Nueva Zelanda2.jpg|Eggs
File:Red billed gull-12.jpg|Comparison of adult (left) and immature (right) red-billed gulls in flight
File:Red-billed gull colony, Kaikōura, New Zealand 08.jpg|Sea gull colony in Kaikōura
File:Red billed gull 2.jpg|alt=2021 photo|2021 photo
</gallery>

==Notes==
{{notelist}}

==References==
{{Reflist}}
*Mills, J. A. (1994).  Extra-pair copulations in the Red-Billed Gull: Females with high-quality, attentive males resist.  ''Behaviour, 128'', 41–64.
* Pons J.M., Hassanin, A., and Crochet P.A.(2005). ''Phylogenetic relationships within the Laridae (Charadriiformes: Aves) inferred from mitochondrial markers.'' Molecular Phylogenetics and Evolution 37(3):686-699
*Tasker, C. R., & Mills, J. A. (1981). A functional analysis of courtship feeding in the Red-billed Gull, ''Larus Novaehollandiae scopulinus''.  ''Behaviour, 77'', 222ff

==External links==
{{Commons|Chroicocephalus novaehollandiae scopulinus}}
* [http://nzbirdsonline.org.nz/species/red-billed-gull Red-billed Gull, New Zealand Birds Online]

{{Gulls}}
{{Taxonbar|from1=Q76472|from2=Q27608860}}

[[Category:Chroicocephalus|red-billed gull]]
[[Category:Endemic birds of New Zealand]]
[[Category:Birds described in 1844|red-billed gull]]
[[Category:Taxa named by Johann Reinhold Forster]]
[[Category:Subspecies]]