Kiwi

Kiwi
North Island Brown Kiwi
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Struthioniformes (or Apterygiformes)
Family: Apterygidae
Gray, 1840[1]
Genus: Apteryx
Shaw, 1813[1]
Species

Apteryx haastii
Great Spotted Kiwi
Apteryx owenii
Little Spotted Kiwi
Apteryx rowi
Okarito Brown Kiwi
Apteryx australis
Brown Kiwi
Apteryx mantelli
North Island Brown Kiwi
Synonyms

Apternyx [sic] Swainson 1837
Stictapteryx Iredale & Mathews 1926
Kiwi Verheyen 1960

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.[2] 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.

Contents

Species

There are five accepted species of kiwi (one of which has four sub-species), plus one to be formally described.

The distribution of each species of kiwi
From left to right : Brown Kiwi (Apteryx australis), Little Spotted Kiwi (Apteryx owenii), and Great Spotted Kiwi (Apteryx haastii), Auckland War Memorial Museum

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 in 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.

Biology

Evolution

It was long presumed that the kiwi's closest relatives were 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's closest relatives are the Emu and the cassowaries. This theory suggests that the kiwi's ancestors 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 New Zealand's native moa, they believe that the kiwi is more closely related to its Australian cousins.[5]

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.[6] 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 beak. 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.[6]

Relative size of the egg

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.[7] They are unique among other birds in that they have a functioning pair of ovaries.[6] 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,[8] 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.[9][10] Eggs are smooth in texture, and are ivory or green-ish white.[11] 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.[6] 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.[12]

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 kiwi's bristly, hair-like, two-branched feathers. 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 (16 oz) 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.[6]

Relationship with humans

Kiwi on 1898 New Zealand stamp.

Kiwi and Māori

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.[13] 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.[14]

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

The London Zoo was the first zoo to hold a kiwi, in 1851. The first captive breeding took place in 1945.[15] As of 2007 only 13 zoos outside Australasia hold kiwi.[16] The Frankfurt Zoo has 12, the Berlin Zoo has 7, Walsrode Bird Park has 1, the Alphen Birdpark 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.[17]

Etymology

The widely recognised origin for the name Kiwi (pronounced /ˈkiːwiː/ KEE-wee), is from the Māori language (1825–1835)[18] and as "of imitative origin" from the call.[19] However, there is another theory that the name stems from the fact that, with its long decurved bill and hairy brown body, it is similar to the Polynesian word kivi, used for the bristle-thighed curlew. So when the first settlers arrived, they simply reused this word for the new found bird.[14]

The genus name Apteryx is derived from Ancient Greek "without wing": a-, "without" or "not"; pterux, "wing".[20]

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, kiwis 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 kiwis are prominent in the coat of arms, crests and badges of many New Zealand cities, clubs and organisations.[11][21]

The New Zealand dollar is often referred to as "the kiwi dollar".[22]

Program for saving endangered Kiwi

To protect the endangered Kiwi, a number of trusts and protection programme have been set up. These include:

See also

Footnotes

  1. ↑ 1.0 1.1 Brands, S. (2008)
  2. ↑ San Diego Zoo
  3. ↑ "Rowi: New Zealand native land birds". New Zealand Department of Conservation (DOC). http://www.doc.govt.nz/conservation/native-animals/birds/land-birds/kiwi/rowi-formerly-okarito-brown-kiwi/. Retrieved 2009-07-25. 
  4. ↑ 4.0 4.1 Shepherd, L.D. & Lambert, D.M. (2008)
  5. ↑ News in Science
  6. ↑ 6.0 6.1 6.2 6.3 6.4 Davies, S. J. J. F. (2003)
  7. ↑ SavetheKiwi.org.nz formerly KiwiRecovery.org
  8. ↑ Auckland Zoo's Official Guide Book. In the section on wilderness New Zealand
  9. ↑ Savethekiwi.org
  10. ↑ San Diego Zoo, Kiwi
  11. ↑ 11.0 11.1 "The Kiwi Bird, New Zealand's Indigenous Flightless Bird". http://www.chemistry.co.nz/kiwibird.htm. Retrieved 2009-01-16. 
  12. ↑ Piper, R. (2007)
  13. ↑ "Kiwi and people: early history", Te Ara
  14. ↑ 14.0 14.1 http://www.savethekiwi.org.nz/about-the-bird/kiwi-a-maori/kiwi-a-maori.html
  15. ↑ "Captive management plan for kiwi". New Zealand Department of Conservation. June 2004. p. 10. http://www.doc.govt.nz/upload/documents/science-and-technical/tsop24.pdf. Retrieved 17 August 2009. 
  16. ↑ Zoo and Wild Animal Medicine Current Therapy, Murray E. Fowler, R. Eric Miller, Elsevier Health Sciences, 2007, p. 215.
  17. ↑ Gibson, Eloise (04/29/2010)
  18. ↑ Random House Unabridged Dictionary
  19. ↑ The American Heritage Dictionary of the English Language
  20. ↑ Gotch, A. F. (1995))
  21. ↑ "The Kiwi, NZ Search". http://www.nzs.com/about-new-zealand/the-kiwi/. Retrieved 2009-01-16. 
  22. ↑ Kiwi dollar nears six year low against greenback. NZ Herald

References

External links