Fr: Huîtrier de Finsch
Maori: Torea
Ang: South Island (Pied) Oystercatcher
All: South Inselausternfischer
Esp: Ostrero de Finsch
Ita: Beccaccia di mare di South Island
Nd: Finsch' Scholekster
Sd: Sydstrandskata
Photographers:
Patrick Ingremeau
TAMANDUA
Ian McHenry
My New Zealand Birds
Text by Nicole Bouglouan
Sources:
KNOW YOUR NEW ZEALAND BIRDS by Lynnette Moon - New Holland Publishers – ISBN: 1869660897
SHOREBIRDS by Peter Hayman, John Marchant and Tony Prater – Christopher Helm – 1986 – ISBN: 0747014035
New Zealand bird status between 2008 and 2012
Te Ara – The Encyclopedia of New Zealand
Wikipedia, the free encyclopaedia
South Island (Pied) Oystercatcher
Haematopus finschi
Charadriiformes Order – Haematopodidae Family
INTRODUCTION:
The South Island (Pied) Oystercatcher is also known as “SIPO”. It was formerly a subspecies of the Pied Oystercatcher (H. longirostris).
This species is one of the two oystercatchers found in New Zealand. As it is becoming a full species, the SIPO is therefore endemic to this country, along with the Variable Oystercatcher, but some debate is still under way.
DESCRIPTION OF THE BIRD:
Biometrics:
Length: 46 cm
Weight: 550 g
The adult has black-and-white plumage. Head, neck, upper back, wings, tail and breast are black. We can see a large white wingbar across the greater coverts. The white rump extends well up the back to end in a point.
The South Island (Pied) Oystercatcher differs from the pied morph of the Variable Oystercatcher by the white peak between breast and folded wing.
On the underparts, there is a sharp border on the lower breast between the black breast and the white rest of underparts. The underwing shows black leading and trailing edges, and dark primary flight feathers.
On the black head, the long, stout bill is red (84-95 mm in length). The eyes are red, surrounded by red eyering. Legs and feet are pinkish.
Both sexes are similar.
The juvenile shows brownish wash on plumage. The bill is darker red. Legs and feet are dull pink.
RANGE:
The South Island (Pied) Oystercatcher breeds in the South island, E of the Southern Alps in New Zealand. After the breeding season, it migrates to the coastal areas of North and South Islands.
HABITAT:
The South Island (Pied) Oystercatcher frequents estuaries and harbours. It breeds inland on braided shingle riverbeds, farmland, fringes of lakes, high country grasslands and coastal areas near estuaries and lagoons.
During winter, they form small or large flocks of up to several thousand birds resting on shellbanks and sandspits in estuaries and bays.
CALLS AND SONGS: SOUNDS BY XENO-CANTO
The South Island (Pied) Oystercatcher gives clear, loud shrill “kleep kleep” while flying strongly. It utters a rapid “pic pic pic” when alarmed and loud piping calls in territorial defence.
BEHAVIOUR IN THE WILD:
The South Island (Pied) Oystercatcher does not catch oyster as its name suggests! It feeds mainly on small fish, molluscs and marine worms by probing with its long bill. It opens the shellfish by stabbing with the bill. Then, it twists the bill to loosen the flesh.
When it feeds in pastures, it takes earthworms and grubs.
At high tide, they feed in loose flocks at water’s edge. However, adults and juveniles are able to swim over short distances like from bank to bank.
During the breeding season, The South Island (Pied) Oystercatcher often returns to the same site. Most pairs have long-term pair-bonds and ritualized social behaviour.
The SIPO defends aggressively its territory against terrestrial and aerial predators. It mobs the intruder and feigns injury or false brooding to lead it away from the nest-site.
Pairs perform ritual courtship displays such as “piping dances”. Two or three birds bow their heads and move with short-quick steps. They call with high-pitched rising trills, lowering towards the end of the display.
The South Island (Pied) Oystercatcher migrates after breeding to the coastal areas of North and South Islands, and it occurs in estuaries, bays, beaches, sand flats and intertidal mudflats in North Island.
This bird performs fast flight with strong, regular wingbeats.
REPRODUCTION OF THIS SPECIES:
The breeding season occurs in spring and summer, from September to November, although the birds which are living in higher range may breed later.
The nest is a scrape in earth or shingle, lined with twigs. Some ornaments can be added, such as tiny stones and shells. But some nests can be a mound or a raised area of sand, gravel or soil, providing good visibility around the nest-site.
The female lays 1-3 blotched or speckled eggs, making them almost invisible on the ground. Both adults incubate during 24-28 days. The chicks are precocial and able to leave the nest very soon after hatching. They have brownish down on head and upperparts, and white below. The short bill is blackish like the eyes, and legs and feet are pale flesh. They are fed by their parents until they fledge, about 4-6 weeks after hatching. They can breed at 2-3 years old.
PROTECTION / THREATS / STATUS:
The South Island (Pied) Oystercatcher has survived the usual threats since human impact, such as introduction of mammalian predators, hunting until 1940, and invasive tall vegetation on their breeding sites.
Today, this species is facing other threats such as changes in breeding habitat, pollution at winter feeding areas, and increase of human disturbance at coastal sites with vehicles, dogs and recreational activities.
The South Island (Pied) Oystercatcher is currently evaluated as Least Concern, but its population is declining. It was estimated at 112,000 individuals in 1983-1994, and 110,000 birds in 2002, with a predicted decline of 10/50%.
