The South Island oystercatcher or South Island pied oystercatcher (''Haematopus finschi'') is one of two common

oystercatcher The oystercatchers are a group of waders forming the family (biology), family Haematopodidae, which has a single genus, ''Haematopus''. They are found on coasts worldwide apart from the polar regions and some tropical regions of Africa and Sout ...

species found in

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 ...

. Its name is often contracted to the acronym "SIPO" (rhyming with "typo"). The indigenous

Māori Māori or Maori can refer to: Relating to the Māori people * Māori people of New Zealand, or members of that group * Māori language, the language of the Māori people of New Zealand * Māori culture * Cook Islanders, the Māori people of the Co ...

name is . The scientific name commemorates the German ethnographer, naturalist and colonial explorer Friedrich Hermann Otto Finsch (8 August 1839 – 31 January 1917, Braunschweig).Jobling, James A. (2010). Bloomsbury Publishing, ed. The Helm dictionary of scientific bird names from aalge to zusii. Londres: Christopher Helm. p. 159. ISBN 1408133261.

Description

The South Island oystercatcher is easily identifiable as a pied oystercatcher – a large wader with striking black and white plumage, long red-orange bill, and red legs. It is distinguished from the pied morph of the

variable oystercatcher The variable oystercatcher (''Haematopus unicolor'') is a species of wader in the family Haematopodidae. It is Endemism, endemic to New Zealand. The Māori name is tōrea-pango. They are also known as 'red bills'. Description "Variable" refers ...

by a white lower back, more white on the wing, and a demarcation line of black and white further forward on the breast, and from the pied oystercatcher of Australia by a longer bill and shorter legs, as well as the forward demarcation line of white on the back being pointed rather than square. It is 46 cm in length; its wingspan is 80–86 cm; it weighs 550 g.Marchant, S.; Higgins, P.J.; & Davies, J.N. (eds). (1994). ''Handbook of Australian, New Zealand and Antarctic Birds. Volume 2: Raptors to Lapwings''. Oxford University Press: Melbourne.

Distribution and habitat

The South Island oystercatcher is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to New Zealand where it breeds inland on the

South Island The South Island ( , 'the waters of Pounamu, Greenstone') is the largest of the three major islands of New Zealand by surface area, the others being the smaller but more populous North Island and Stewart Island. It is bordered to the north by ...

, after which most of the population moves to estuaries and harbors on the

North Island The North Island ( , 'the fish of Māui', historically New Ulster) is one of the two main islands of New Zealand, islands of New Zealand, separated from the larger but less populous South Island by Cook Strait. With an area of , it is the List ...

. It has been recorded occasionally as a vagrant on

Norfolk Island Norfolk Island ( , ; ) is an States and territories of Australia, external territory of Australia located in the Pacific Ocean between New Zealand and New Caledonia, directly east of Australia's Evans Head, New South Wales, Evans Head and a ...

Lord Howe Island Lord Howe Island (; formerly Lord Howe's Island) is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, part of the Australian state of New South Wales. It lies directly east of mainland Port ...

, and the eastern coast of mainland

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 ...

. Its breeding habitat comprises

braided river A braided river (also called braided channel or braided stream) consists of a network of river channel (geography), channels separated by small, often temporary, islands called ''braid bars'' or, in British English usage, ''aits'' or ''eyots''. ...

systems, open paddocks, cultivated land, lake beaches,

subalpine Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...

tundra In physical geography, a tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: #Arctic, Arctic, Alpine tundra, Alpine, and #Antarctic ...

, and herb fields. Non-breeding habitat includes coastal estuaries, bays, beaches, sand flats, and

intertidal The intertidal zone or foreshore is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can include several types of habitats with various sp ...

mudflat Mudflats or mud flats, also known as tidal flats or, in Ireland, slob or slobs, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A global analysis published in 2019 suggested that tidal ...

Behaviour

Food

It mostly feeds on mollusks and worms. A major food source for oystercatchers is the New Zealand cockle, '' Austrovenus stutchburyi''. It is estimated that an individual oystercatcher can eat around 200,000 cockles in a single year.

Voice

It has piping calls, which are used socially and aggressively, as well as a piercing alarm call and a quiet flight call.

Breeding

It nests in sand scrapes on farmland or gravel banks in braided rivers. Its clutch typically consists of two, sometimes three, brown eggs, which are blotched dark and pale brown. Its incubation period is 24–28 days, with both sexes incubating. Its young are

precocial Precocial species in birds and mammals are those in which the young are relatively mature and mobile from the moment of birth or hatching. They are normally nidifugous, meaning that they leave the nest shortly after birth or hatching. Altricial ...

and

nidifugous In biology, nidifugous ( , ) organisms are those that leave the nest shortly after hatching or birth. The term is derived from Latin ''nidus'' for "nest" and ''fugere'', meaning "to flee". The terminology is most often used to describe birds and w ...

, fledging 6 weeks after hatching.

Parasites

The flatworm '' Curtuteria australis'' is a parasite that infects South Island oystercatchers. Larvae which infect cockles are eaten by the birds, which in turn lay eggs and are excreted by the oystercatchers. The eggs are injected by

whelk Whelks are any of several carnivorous sea snail species with a swirling, tapered shell. Many are eaten by humans, such as the common whelk of the North Atlantic. Most whelks belong to the family Buccinidae and are known as "true whelks." Othe ...

s, which in turn are consumed by cockles.

Conservation

The population of this species declined, mainly because of hunting, during the late 19th century and early 20th century but, with legal protection since 1940, has since been increasing. In 2002 the total population was estimated to be 110,000. Its conservation status is of

Least Concern A least-concern species is a species that has been evaluated and categorized by the International Union for Conservation of Nature (IUCN) as not being a focus of wildlife conservation because the specific species is still plentiful in the wil ...

.BirdLife International. (2006). Species factsheet: ''Haematopus finschi''. Downloaded from http://www.birdlife.org on 12 February 2007

References

{{Taxonbar, from=Q1267686 South Island oystercatcher Birds of the South Island South Island oystercatcher Endemic birds of New Zealand Taxa named by Gustav Heinrich Martens