Oystercatchers
Oystercatchers are stocky birds with bright eye-rings and long colourful bills. Their diet is much more varied than their name implies.
- Pied oystercatcher
The pied oystercatcher or torea is the most common oystercatcher in New Zealand, numbering around 112,000 birds in 1994. The New Zealand subspecies (Haematopus ostralegus finschi) is the South Island pied oystercatcher or SIPO. It has a black head and upper surfaces, and a white belly. A white Y pattern between the chest and the folded wing distinguishes it from the pied phase of the variable oystercatcher. The pied oystercatcher has a red bill, orange eye-ring and short pink legs, measures 46 centimetres and weighs 550 grams.
In early spring, pied oystercatchers migrate from beaches and estuaries to inland rivers or farmland, mainly in the South Island, where they breed from August. Nests are a shallow scrape on open riverbeds or farmland. They lay one to three brown, blotched eggs, the parents sharing incubation. Chicks can fly at six weeks. From December, after raising their young for the year, they return to winter feeding grounds in the North or South Island, where large flocks gather on sand spits and estuaries, or near a river mouth. Their chief ports of call include Farewell Spit, the Firth of Thames, and Kaipara and Manukau harbours.
On the coast, they probe into mud or wet sand, or picking from the surface, they feed on molluscs, estuarine worms and small fish. Inland, they feed on worms and grubs.Pied oystercatchers start breeding from the age of four or five, and they live up to 27 years.
- Variable oystercatcher
The variable oystercatcher (Haematopus unicolor, torea or toreapango) is found on rocky and sandy beaches. It is rare – there were around 3,500 birds in 1994, and they are found only in New Zealand. Also known as the black oystercatcher, it varies from black and white to pure black, which is more common further south. It has a red bill and red-orange eye-ring, and pink legs. Larger than the pied oystercatcher, it measures 48 centimetres and weighs 725 grams.
The variable oystercatcher has different colour phases: some birds are all black, some have a smudged black and white belly, and some a pure white belly. This third type can be hard to distinguish from the pied oystercatcher, also black and white. The thing to look for on the variable oystercatcher is the more blurred boundary between black and white across the chest. There is also no white line between the chest and the folded wing.
These birds remain around the coast to breed. The diet, therefore, is largely marine, including mussels, oysters, limpets and crabs. After heavy rain they will invade coastal fields for a meal of worms and insect larvae. Nests are a shallow scrape above spring-tide level, and two or three eggs (but up to five) are laid from September to December. Both parents incubate, and chicks are able to fly at six weeks.
Once in serious decline due to hunting, the variable oystercatcher is now protected. They live for up to 27 years.
- Chatham Island oystercatcher
With a population of only 220 birds in 2004, the endemic Chatham Island oystercatcher (Haematopus chathamensis ) is endangered. However, in the 1980s and 1990s there were only 100. With assistance from conservation managers, it is hoped that numbers will soon reach 500.
This species is confined to the Chatham Islands and South East and Pitt islands. They measure 48 centimetres and weigh 600 grams. Cats, the flightless weka, and skuas are the main predators, with the added danger of occasional high seas swamping the nests.
Since a conservation programme in the late 1990s to trap the predators and restore habitat, the bird has made a swift comeback. However, given their restricted habitat, it is unlikely the species will ever be numerous.
These birds live on the coast all year, feeding on molluscs, crabs, invertebrates, and marine worms. Starting in October–December or later, they nest in a shallow scrape often under coastal vegetation for protection from skuas. They lay one to three olive-brown spotted eggs. Both adults incubate, females mainly during daylight. Chicks can fly at seven weeks old. They usually live about eight years, but can live to 19.
To help Chatham Island oystercatchers breed, conservation staff place old tyres filled with sand on the beach. This makes an ideal platform to lay eggs, safe from high seas. As soon as the bird lays its eggs, staff move the tyre even further away from the threatening waves.
Gannets
There are three gannet species worldwide, all
with adults similar in appearance. The juveniles of the three species are indistinguishable. The northern gannet (Morus bassanus) is a North Atlantic bird which does not venture into southern waters. The African Cape gannet (Morus capensis) appears infrequently in Australian waters. It is recognised by the long black stripe on its throat and a completely black tail. The Australasian gannet (Morus serrator) is found in Australian and New Zealand waters.
With its 2-metre wingspan, golden head and dramatic plunging dives, the white Australasian gannet is an easily identified seabird. Adult gannets are about the size of a goose, with black-tipped wings, black central tail feathers and a strong, conical blue-grey beak. Juvenile birds look quite different. In their first year they have speckled brown feathers on their upper body, and white undersides. Each year more white feathers appear on their backs, and the birds acquire their adult appearance by five years of age.
Australasian gannet numbers in New Zealand increased markedly during the second half of the 20th century – from an estimated 27,000 breeding pairs in the first census of 1947, to 46,000 in the 1980–81 count. New Zealand is home to 87% of the total population of adult birds.
Māori made expeditions to the rocky breeding grounds of gannets, or tākapu, catching the young birds for food and the adults for their bones and plumage. Bones were fashioned into chiselling tools and used for applying elaborate facial moko (tattoos). The valuable white feathers were used to decorate canoes, or were worn by high-ranking individuals.
New Zealand is one of the best places in the world to view Australasian gannets. There are three accessible mainland breeding colonies – at Cape Kidnappers, Muriwai and Farewell Spit. There are also 21 offshore gannetries, and an expanding population. The largest breeding colonies are on the Three Kings Islands, Gannet Island, and White Island. The birds live all around New Zealand’s coastal waters, especially north of Cook Strait. They are also found around much of the Australian coast, including Lord Howe and Norfolk islands.
Cape Kidnappers 
Gannets usually breed in colonies on offshore islands. However, in 1880 a New Zealand naturalist, Henry Hill, noted that about 50 gannets had started breeding on an elevated headland at Cape Kidnappers in Hawke’s Bay. The area was protected as a reserve in 1915 and the gannet population steadily increased. By the late 1990s there were 6,500 breeding pairs in four sub-colonies. For nearly a century Cape Kidnappers remained the only mainland colony in New Zealand.
Muriwai
In the 1980s a colony established itself north of Auckland at Muriwai Beach. Two headlands were fenced off to protect nesting gannets that had arrived from nearby Motutara Island. However, the fences eventually prevented the colony from expanding. Once they were removed, in 1996–97, the population more than doubled within four years.
Farewell Spit 
Unlike the Cape Kidnappers and Muriwai colonies, which are on elevated sites, the most recently established colony is practically at sea level. The birds breed on shell banks at Farewell Spit, at the north-west tip of the South Island. Beginning with 75 breeding pairs in 1983, the colony grew to around 600 pairs by 1987. The site is vulnerable to storms; the colony was nearly wiped out in January 1997 by Cyclone Drena, but eventually recovered.
Kingfisher
Kotare, the kingfisher, is around here in numbers again and it is good to
hear their friendly piping as well as their harsh alarm rattle. They seem
to have had a good breeding season as many are juveniles, being
brownish in colour, unlike the brilliant blue and green of the adults.
The species Halcyon sanctus is found in New Guinea, Australia,
Tasmania, New Caledonia, the Solomon, Kermadec, Lord Howe, Norfolk
and Loyalty Islands. The New Zealand sub-species, vagans, is
distinguished from the Australian sub-species by its larger size and
broader bill and generally by the distinctiveness of its green and blue
colours.
Halcyon is the Greek word for kingfisher and refers to a bird fabled to
breed about the time of the winter solstice in a nest floating on the sea
and to charm the wind and waves so that the sea was then specially
calm, hence halcyon days. The specific name of sanctus, the Sacred
Kingfisher, was, according to the ornithologist W.H. Oliver, bestowed on
the species as far back as 1782 because of the veneration paid to the
bird in some Pacific Islands.
Kotare is distinguished by its habit of perching in a prominent place and
waiting for its prey to appear. The collective noun of “a concentration of
kingfishers”, would seem to be entirely appropriate. The bird is all head
and shoulders with a very broad bill, made, it would seem, for driving
into clay banks or a tree to make nesting holes.
According to Oliver, it is a fearless bird and readily attacks mammals and
birds of its own size and larger. “Starlings are driven away, red billed
gulls put to flight, a Tui killed, cats and dogs blinded in one eye and even
weasels attacked. Every kind of small animal is attacked, killed and
eaten by the kingfisher.
The mouse is a first favorite and the bird’s sharp eyes and quick actions are usually effective when one comes into view. Before being swallowed the victim is pulped and its bones broken by battering on the kingfisher’s perch. Small birds such as Tauhou, the white eye, are eaten and lizards where they are plentiful. Larger insects also form part of the diet.“
Fish form only a small part of their diet but whitebait are taken in the
lower reaches of the rivers in spring and goldfish in ponds are not safe.
Buller, Walter Lawry, Birds of New Zealand. They have been photographed diving into the water after prey with theirwings clapped to their sides like a gannet.
They nest in a burrow either in a clay bank or a tree, very often a
decaying willow. As described by many writers and observers, to start a
tunnel they sit an a branch slightly above and several metres away from
the site and fly straight at it, neck outstretched and uttering a peculiar
whirring call, and strike it forcedly with the bill tip. They continue until
the hole is big enough to perch in and scoop out. The nesting burrow can
be as much as 24cm long and will be used year after year.
The female does most of the brooding while the male supplies the food.
They are bad housekeepers and the nests are often quite filthy.
Elsdon Best has expressed some surprise that Maori never used the
feathers of Kotare for decorative cloaks, considering the bird’s very
colourful feathers. “The young of this bird were taken from the nest in
former times for the pot, or rather steam pit”, he has written. “Some
Maori, however, were prejudiced against them because it was observed
that they ate lizards which are regarded as guardians of the mauri of the
forest.” They are not, it seems venerated by Maori.
NZ Dotterel
With the exception of a few birds on the east coast in the Gisborne area and
the very odd bird on the west coast, the Bay of Plenty is as far south as the northern sub–species of the N.Z. dotterel, aquilonius, is found.
It is estimated that there are about 1,350 of this subspecies and rather less than 100 of the southern obscurus subspecies which is found on Stewart Island and which is a slightly larger bird. In the eastern Bay of Plenty the birds nest on the dunes at several estuaries in the Opotiki area, namely those of the Waiotahi, Waioeka and Waiaua rivers where they have been extensively studied over recent years by Mr A Glaser of the Department of Conservation. They also nest at Ohiwa harbour further west and at Whangaparaoa near Cape Runaway.
Trapping of potential predators has been carried out by D.O.C over recent years in the Waiotahi, Waioeka and Waiaua areas — the principal predators caught being hedgehogs, stoats, and weasels. The population of black–backed gulls, Larus dominicanus, is reduced when they become dangerous to eggs or chicks.
Over recent years the population of spur–winged plover, Vanellus miles, has
greatly increased and they are often to be found in large numbers in the dotterel nesting areas. Although there are records of these birds molesting chicks their principal detrimental effect is interference with the chicks’ access to food.
As a result of Mr Glaser’s work it has been shown that a dotterel having lost its nest through predation or any other cause will frequently nest again, if necessary, two or three times. Through banding it has been proven that fledglings disperse quite widely, a bird hatched and banded at the Waiaua estuary was seen at Pollen Island in the Waitemata Harbour area.
After nesting the local dotterels flock at Ohiwa Harbour, starting to assemble usually in late February. In recent years this flock, at its height, has amounted to around 70 birds. It usually starts to disperse in May. For some reason they seem to populate the furthest of the three estuaries, Waiaua first. The birds are very territorial and much squabbling takes place when a bird encroaches on someone else’s patch.
One advantage that the dotterel nesting areas in this region have over many of those further north is that they are not plagued by holiday makers to any great extent; in some places unless chicks are fledged by Christmas little hope is held out for their survival as a result of human interference.
A bird with some fascinating habits, Tuturiwhatu live only on beaches or sand bars round lagoons. Nesting between early September through to the end of February, they usually choose an area on a wide beach, preferably with good visibility, often near streams or access to fresh water. Most times, the simple nest scrape is against a small patch of drift wood or seaweed. Three eggs are laid over several days, incubation taking 30 + days.
Because of predators (rats, hedgehogs, stoats, gulls, hawks, cats, dogs,) 4 wheel drive vehicles, wave action during storms, picnickers close to nests preventing incubation, very few fledge. However, Tuturiwhatu will lay again, often just 3 weeks after a loss. Last season several pairs I monitored laid 4 times. Twelve eggs is more than the adult body weight so those unsuccessful breeders do not live a long life. Males also have their lives shortened as they do the night shift incubation when the majority of the predators are active.
I find an endearing habit is the male running to greet an intruder invading his chosen territory. Also, if I start moving driftwood or flotsam, I get interested spectators. Dotterels very closely inspect any change to their territory.
To lure away human invaders, they will frequently run in front of you, semi–crouched with the head turned back to make sure you are following. If that is unsuccessful the broken wing ploy is tried. I have witnessed a dotterel chase a black back gull, a white face heron, a paradise shellduck and even a pair of variable oystercatchers that came too close to its eggs.
Frequently dotterels and oystercatchers nest in close proximity and do a very good job minding intruders to stay out of their nest area. I have witnessed a male dotterel trying to turn a oystercatcher egg while the parent birds were away feeding.
