Kiwi

Kiwi are flightless birds endemic to New Zealand, in the genus Apteryx and family Apterygidae.

At around the size of a domestic chicken, kiwi are by far the smallest living ratites and lay the largest egg in relation to their body size of any species of bird in the world. There are five recognised species, all of which are endangered; all species have been adversely affected by historic deforestation but currently large areas of their forest habitat are well protected in reserves and national parks. At present, the greatest threat to their survival is predation by invasive mammalian predators.

The kiwi is a national symbol of New Zealand – indeed, the association is so strong that the term Kiwi is used, all over the world, as the colloquial demonym for New Zealanders.

Species
There are five accepted species of kiwi (one of which has four sub-species), plus one to be formally described.
 * The largest species is the Great Spotted Kiwi or Roroa, Apteryx haastii, which stands about 45 cm high and weighs about 3.3 kg. (Males about 2.4 kg) It has grey-brown plumage with lighter bands. The female lays just one egg, which both parents then incubate. Population is estimated to be over 20,000, distributed through the more mountainous parts of northwest Nelson, the northern West Coast, and the Southern Alps.
 * The very small Little Spotted Kiwi, Apteryx owenii is unable to withstand predation by introduced pigs, stoats and cats, which have led to its extinction on the mainland. About 1350 remain on Kapiti Island and it has been introduced to other predator-free islands and appears to be becoming established with about 50 'Little Spots' on each island. A docile bird the size of a bantam, it stands 25 cm high and the female weighs 1.3 kg. She lays one egg which is incubated by the male.
 * The Okarito Kiwi, also known as the Rowi or Okarito Brown Kiwi, Apteryx rowi, first identified as a new species in 1994, is slightly smaller, with a greyish tinge to the plumage and sometimes white facial feathers. Females lay as many as three eggs in a season, each one in a different nest. Male and female both incubate. Distribution of these kiwi are limited to a small area on the west coast of the South Island of New Zealand, however studies of ancient DNA have revealed that in prehuman times it was far more widespread up the west coast of the South Island and was present in the lower half of the North Island where it was the only kiwi species detected.
 * The Southern Brown Kiwi, Apteryx australis, relatively common species of kiwi known from south and west parts of the South Island that occurs at most elevations. It is approximately the size of the Great Spotted Kiwi and is similar in appearance to the Brown Kiwi but its plumage is lighter in colour. Ancient DNA studies have shown that in prehuman times the distribution of this species included the east coast of the South Island.  There are several subspecies of the Tokoeka recognised:
 * The Stewart Island Southern Brown Kiwi, Apteryx australis lawryi, is a subspecies of Tokoeka from Stewart Island.
 * The Northern Fiordland Southern Brown Kiwi (Apteryx australis ?) and Southern Fiordland Tokoeka (Apteryx australis ?) live in the remote southwest part of the South Island known as Fiordland. These sub-species of Tokoeka are relatively common and are nearly 40 cm tall.
 * The Haast Southern Brown Kiwi, Apteryx australis ‘Haast’, is the rarest subspecies of kiwi with only about 300 individuals. It was identified as a distinct form in 1993. It only occurs in a restricted area in the South Island's Haast Range of the Southern Alps at an altitude of 1500 m. This form is distinguished by a more strongly downcurved bill and more rufous plumage.
 * The North Island Brown Kiwi, Apteryx mantelli or Apteryx australis before 2000 (and still in some sources), is widespread in the northern two-thirds of the North Island and, with about 35,000 remaining, is the most common kiwi. Females stand about 40 cm high and weigh about 2.8 kg, the males about 2.2 kg. The North Island Brown has demonstrated a remarkable resilience: it adapts to a wide range of habitats, even non-native forests and some farmland. The plumage is streaky red-brown and spiky. The female usually lays two eggs, which are incubated by the male.

Analysis of mitochondrial DNA, ecology, behaviour, morphology, geographic distribution and parasites of the North Island Brown Kiwi has led scientists to propose that the Brown Kiwi is three distinct species. The North Island Brown Kiwi; the Okarito Brown Kiwi (Rowi), whose distribution is restricted to a single site on the West Coast of the South Island of New Zealand; and a third distinct population of the North Island Brown Kiwi, the Southern Tokoeka, distributed in the lowland forest to the north of Franz Josef glacier in the South Island and on Stewart Island/Rakiura, with a small population near Haast being another possibly distinct species, the Haast Tokoeka.

Evolution
It was long presumed that the kiwi was closely related to the other New Zealand ratites, the moa. However, recent DNA studies indicate that the ostrich is more closely related to the moa and the kiwi is more closely related to the emu and the cassowaries. This theory suggests that the ancestors of the kiwi arrived in New Zealand from elsewhere in Australasia well after the moa. According to British scientists, the kiwi may be an ancient import from Australia. Researchers at Oxford University have found DNA evidence connected to Australia's emu and the ostrich of Africa. Upon examining DNA from the moa, they believe that the kiwi is more closely related to its Australian cousins.

Behaviour and ecology
Before the arrival of humans in the 13th century or earlier, New Zealand's only endemic mammals were three species of bat, and the ecological niches that in other parts of the world were filled by creatures as diverse as horses, wolves and mice were taken up by birds (and, to a lesser extent, reptiles).

Kiwi are shy and usually nocturnal. Their mostly nocturnal habits may be a result of habitat intrusion by predators, including humans. In areas of New Zealand where introduced predators have been removed, such as sanctuaries, kiwi are often seen in daylight. They prefer subtropical and temperate podocarp and beech forests, but they are being forced to adapt to different habitat, such as sub-alpine scrub, tussock grassland, and the mountains. Kiwi have a highly developed sense of smell, unusual in a bird, and are the only birds with nostrils at the end of their long beaks. Kiwi eat small invertebrates, seeds, grubs, and many varieties of worms. They also may eat fruit, small crayfish, eels and amphibians. Because their nostrils are located at the end of their long beaks, Kiwi can locate insects and worms underground without actually seeing or feeling them, due to their keen sense of smell. Once bonded, a male and female kiwi tend to live their entire lives as a monogamous couple. During the mating season, June to March, the pair call to each other at night, and meet in the nesting burrow every three days. These relationships may last for up to 20 years. They are unique among other birds in that they have a functioning pair of ovaries. Kiwi eggs can weigh up to one quarter the weight of the female. Usually only one egg is laid per season. The kiwi lays the biggest egg in proportion to its size of any bird in the world, so even though the kiwi is about the size of a domestic chicken, it is able to lay eggs that are about six times the size of a chicken's egg. Eggs are smooth in texture, and are ivory or green-ish white. The male incubates the egg, except for the Great spotted kiwi, A. haastii, where both parents are involved. The incubation period is 63–92 days. Producing the huge egg places a lot of demands on the female. For the thirty days it takes to grow the fully developed egg the female must eat three times her normal amount of food. Two to three days before the egg is laid there is little space left inside the female for her stomach and she is forced to fast.

Morphology
Their adaptation to a terrestrial life is extensive: like all ratites they have no keel on the breastbone to anchor wing muscles, and barely any wings. The vestiges are so small that they are invisible under the bristly, hair-like, two-branched feathers of the kiwi. While birds generally have hollow bones to minimise weight and make flight practicable, kiwi have marrow, in the style of mammals. With no constraints on weight due to flight requirements, some Brown Kiwi females carry and lay a single 450 g egg. Like most other ratites, they have no preen gland. Their bill is long, pliable, and sensitive to the touch, and their eyes have a reduced pecten. Their feathers lack barbules, and aftershafts, and they have large vibrissae around the gape. They have 13 flight feathers, no tail, just a small pygostyle. Finally, their gizzard is weak and their caecum is long and narrow.

Kiwi and Māori
The Māori traditionally believe that kiwi are under the protection of Tane Mahuta, god of the forest. Kiwi feathers are particularly important to Māori, as they are used for kahu-kiwi – ceremonial cloaks. Today, while kiwi feathers are still used, they are gathered from kiwi that die naturally or through road accidents or predation, and Māori no longer hunt kiwi, but consider themselves their guardians.

Discovery and documentation
The first kiwi specimen to be studied by Europeans was a kiwi skin brought to George Shaw by Captain Andrew Barclay aboard the ship Providence, who was reported to have been given it by a sealer in Port Jackson (Sydney Harbour) around 1811. George Shaw gave the kiwi its scientific name and drew sketches of the way he imagined a live bird to look which appeared as plates 1057 and 1058 in volume 24 of The Naturalist's Miscellany in 1813.

Zoos
In 1851, London Zoo became the first zoo to keep kiwi. The first captive breeding took place in 1945. As of 2007 only 13 zoos outside New Zealand hold kiwi. The Frankfurt Zoo has 12, the Berlin Zoo has 7, Walsrode Bird Park has 1, the Washington Zoo has 3, the Avifauna Bird Park in the Netherlands has 3, the San Diego Zoo has 5, the San Diego Wild Animal Park has 1, the Smithsonian National Zoological Park has 5, the Smithsonian Conservation Biology Institute has 1 and the Columbus Zoo and Aquarium in Columbus, Ohio has 3.

Etymology
The Māori language word kiwi is generally accepted to be "of imitative origin" from the call. However, linguists derive the word from Proto-Nuclear Polynesian *kiwi, which refers to Numenius tahitiensis, the Bristle-thighed Curlew, a migratory bird that winters in the tropical Pacific islands. With its long decurved bill and brown body, the curlew resembles the Kiwi. So when the first Polynesian settlers arrived, they simply reused the word for the new-found bird. The genus name Apteryx is derived from Ancient Greek "without wing": a-, "without" or "not"; pterux, "wing".

As a national symbol
The kiwi as a symbol first appeared in the late 19th century in New Zealand regimental badges. It was later featured in the badges of the South Canterbury Battalion in 1886 and the Hastings Rifle Volunteers in 1887. Soon after, the kiwi appeared in many military badges, and in 1906 when Kiwi Shoe Polish was widely sold in the UK and the USA the symbol became more widely known.

During the First World War, the name "kiwi" for New Zealand soldiers came into general use, and a giant kiwi, (now known as the Bulford Kiwi), was carved on the chalk hill above Sling Camp in England. Use has now spread so that now all New Zealanders overseas and at home are commonly referred to as "kiwis".

The kiwi has since become the most well-known national symbol for New Zealand, and the bird is prominent in the coat of arms, crests and badges of many New Zealand cities, clubs and organisations.

The New Zealand dollar is often referred to as "the kiwi dollar".

Programs for saving endangered Kiwi
To protect the endangered Kiwi, a number of trusts and protection programs have been set up.

These include:
 * BNZ save the Kiwi Trust
 * Otanewainuku Kiwi Trust
 * Rainbow Springs
 * Karori Wildlife Sanctuary Trust
 * Moehau Environment Group