Wikipedia

North Island brown kiwi

The North Island brown kiwi (Apteryx mantelli; Apteryx australis or Apteryx bulleri[5] as before 2000, still used in some sources) is a species of kiwi that is widespread in the northern two-thirds of the North Island of New Zealand and, with about 35,000 remaining,[2] it is the most common kiwi species. The eggs laid by the North Island Brown Kiwi are among the largest eggs relative to its body size.[6]

North Island brown kiwi
North Island brown kiwi
(Apteryx mantelli)
Male song
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Infraclass: Palaeognathae
Order: Apterygiformes
Family: Apterygidae
Genus: Apteryx
Species:
A. mantelli
Binomial name
Apteryx mantelli
The distribution of North Island brown kiwi
Synonyms
  • Apteryx australis var. mantelli (Bartlett 1852) Finsch 1872[3][4]
  • Apteryx australis mantelli (Bartlett 1852) Checklist Committee 1953
  • Apteryx bulleri Sharpe 1888
  • Apteryx mantelli mantelli Bartlett 1852
  • Apteryx mantelli novaezelandiae (Lesson 1828)
  • Apteryx australis novaezealandiae (Lesson 1828)
  • Dromiceius novaezelandiae Lesson 1828 nomen nudum

Genetics

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The genome of Apteryx mantelli was sequenced in 2015.[7]

Description

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North Island brown kiwi display size sexual dimorphism, where the females are observably larger than the males.[8]

Females stand about 40 cm (16 in) in height and weigh about 2.6 kg (5.7 lb) and the males about 2 kg (4.4 lb).[9][10] The plumage is streaky red-brown and spiky. The North Island brown kiwi is the only species of kiwi found internationally in zoos.[citation needed]

Taxonomy

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Brown kiwi chick

North Island brown kiwi or Brown Kiwi at the time was first described as Apteryx australis by Abraham Dee Bartlett, in 1813, based on a specimen from Dusky Sound, South Island, New Zealand.[11] This is a monotypic species.[12]

Brown Kiwi (then Apteryx australis) was originally thought to additionally include the rowi (Okarito kiwi) and the tokoeka species. However, through genetic testing in 1994, it was determined that the Tokoeka was a separate, distinct taxon.[13] Once the Tokoeka was separated into its own species, it was given the name Apteryx australis, eventually leading to the official binomial name of Apteryx mantelli to describe the North Island brown kiwi.[14] Soon after, in 2003, more comprehensive genetic tests were performed and it was definitively determined that Rowi was also a separate species[14] and was later given the binomial name Apteryx rowi.[15]

In 2004 an injured bird was found with streaked white around the head and identified by Massey University.[16] The white feathering is likely due to a rarely seen genetic variation sometimes described as a partial albino. Few documented cases exist with only a painting of one found in Ōtorohanga in the 18th century and a specimen in the Canterbury Museum. The injured bird recovered and was introduced into a breeding programme.

Breeding population and trends
Location Population Date Trend
North Island[17] 24550 2016 Increasing
Little Barrier Island[2] 1000 1996 Stable
Ponui Island[18] 2000 (*Hybrid) 2024 Increasing
Kapiti Island[17] unknown Stable?
Kawau Island[2] unknown Stable?
Total (New Zealand) 35,000[19] 2015 Decreasing -2% yr[17]

Range and habitat

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A rare white Apteryx mantelli

North Island brown kiwi (Apteryx mantelli) inhabit four primary regions within New Zealand’s North Island outside of sanctuaries and zoos. This includes Northland and it’s associated islands, the Coromandel, Eastern and Western North Island, New Zealand.[20]

Historically, prior to human colonisation, New Zealand’s indigenous forests covered terrestrial land and provided the assumed primary habitat for all Kiwi species,[21] which thrived in this ecosystem.

In modern day New Zealand, North Island brown kiwi appear to generally prefer densely vegetated lowland and coastal New Zealand indigenous forest as their population densities are highest in these habitats.[8][22][23] However, due to wide spread deforestation and destruction of these native forests post colonisation, the availability and abundance of these preferred habitats has significantly decreased.[24] Although the characteristics of North Island brown kiwi, such as a low reproductive rate and their longevity suggest this species is accustomed to a stable environment, the North Island brown kiwi has been shown to be adaptive to an array of habitat types outside of their historical, ideal habitats.[21] Brown Kiwi can also be found utilising exotic pine forests, overgrown pasture, sand dunes, regenerating forests and forest remnants etc.[21][22][25] This variety in potential habitat usage has been suggested to be possible by the North Island brown kiwi selectively utilising small patches of favourable or ideal habitats amongst other habitat type patches.[21] North Island brown kiwi appear to thrive in exotic forests similarly to indigenous forests. Anecdotal evidence suggests that the population densities, body weights and productivity of North Island brown kiwi in exotic forests is comparable to those within New Zealand indigenous forests.[22] However, as this evidence does not originate from published data, further research needs to be conducted to confirm this claim.

Although there is an acknowledged favourable habitat, the current primary driver of habitat usage in the North Island brown kiwi appears to be food and shelter site availability with purpose/need such as reproduction also being a factor.[21][25] Not in relation to favourable habitat availability within a given territory.[21] For example, nesting sites of the North Island brown kiwi in a territory (purpose – reproduction) containing patches of different habitat types typically were found within or 25m near secondary succession vegetation and/or native vegetation. Kiwi chicks shortly after hatching can only walk short distances and therefore require adequate nearby habitats, which are selected for by nesting parental North Island brown kiwi.[21]

Behaviour

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Foraging

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Kiwi species, such as the North Island brown kiwi, have been found to allocate the majority of their time to foraging, as compared to other behaviours such as vigilance, walking, socialising etc.[8] Their diet primarily consists of invertebrate species, including spiders and worms, which make up 85-95% of their intake, with plant material comprising the remainder.

Over evolutionary history, the visual organs of Apteryx species have been greatly diminished, leading to an overall reduction in their visual field. In fact, Apteryx has the smallest visual field reported of any bird species that rely on non-visual cues for foraging purposes.[26] It has been proposed that this adaptation arose due to their nocturnal, forest-floor foraging behaviour, where low light conditions render visual perception less critical. Under these conditions, a reduction in reliance of visual cues may increase overall fitness by lowering metabolic costs associated with maintaining visual functions and extracting visual information.[26] This suggestion is further supported by the behaviour of other nocturnal, forest floor foraging species that similarly are unable to or do not rely on visual cues for foraging, suggesting convergent evolution across various orders, families and species.[26][27]

Given the reduction in their visual senses, Apteryx species, including the North Island brown kiwi are required to utilise their additional senses, particularly remote touch and smell (olfaction), the most common sense used by North Island brown kiwi, to find prey.[8][26] Remote touch foraging is facilitated by the bill-tip sensory organ found at the end of kiwi species long, narrow slightly down curved beaks.[28] The bill-tip organ consists of mechanoreceptors, such as Herbst corpuscles and terminal cell receptors, found within sensory pits in the bone of the beak tip.[27][28] These mechanoreceptors are sensitive to the vibrations and pressure gradients soil dwelling invertebrates make underground, allowing kiwi to detect their prey without visual or auditory cues.[28][29]

The North Island brown kiwi's most common form of foraging has been observed to be tapping and probing the ground substrate with their beaks.[8] This form of foraging is thought to allow for either olfaction or tactile sensing of prey, with the North Island brown kiwi capable of switching between these sensory modalities depending on the available stimuli.[8][29]

Courtship and Reproduction

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The North Island brown kiwi has been found to primarily engage in monogamous, long term pairings regardless of the sex ratio within a population.[30][31] During courtship and the breeding period, individuals can be observed softly grunting while exhibiting bill to bill raised stretching behavioural displays, thought to reinforce established bonds between pairs and has been observed to occasionally occur before copulation.[30][32] Additionally, prior to copulation, North Island brown kiwi pairs have also been observed to engage in mutual chasing, leaping, loud screeches and snorting.[33]

Once a partnership has formed, the pair prepares their nest for the breeding season within their territory, a process that spans around a 2-month period.[33] This preparation includes burrowing and lining the nests walls and floors with plant material such as fern fronds. Nest sites are typically located underground, within rock crevices or hollowed areas of tree trunks and roots.[33]

After the nest is prepared, the female within the pair contributes her sole parental effort by laying significantly energetically expensive, large, highly nutritious eggs.[30][31] Female North Island brown kiwi can lay up to 5 eggs in a single clutch and up to seven eggs during a breeding season (multiple clutches), though a complete brood that can be properly incubated contains two eggs, which is the average amount of eggs produced by a female in a single clutch.[30][34][35] Once the eggs are laid, the male within a pair solely provides incubation, starting one to seven days post hatch.[30][35] During incubation, male North Island brown kiwi develop a brood patch, where feathers are shed from the lower abdomen, which has been assumed to facilitate more direct contact for enhanced heat transfer, as observed in other Kiwi species.[35][36] The eggs are also regularly turned during incubation.[35]

When males leave their nest for foraging and later return, they often conceal the nest's entrance using surrounding plant material, dirt and plant litter. This has been proposed as an anti-predator mechanism against the New Zealand native Weka bird species. However, it has been further proposed through observational research that this could be a technique utilised to control the amount of humidity within a nest.[35] Generally, incubating males typically leave the nest to forage for roughly a 5-hour period, half of the time spent by non-incubating individuals, suggesting a reduction in foraging time due to parental duties.[34]

Once a chick hatches, it consumes the remaining highly nutritious shell and egg contents. After hatching, chicks do not receive further parental care, as they are born precocious with near full senses and mobility.[34][37] Chicks generally leave the nest within ten days of hatching and remain in their parent's territory, foraging and nesting independently, until they are large enough to establish their territory.[32][34][37]

Vocalisations

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Kiwi species possess unique vocalisations that, like those of other bird species, are proposed to serve in a variety of different social functions.[38] The most common distinctive sound produced by the North Island brown kiwi is termed the “whistle call”, which is performed solo or in a duet. Mates exclusively perform duets as a form of pair communication.[38][39]

Generally, the vocalisations of the North Island brown kiwi are believed to play roles in territory defence, social communication and reproductive/ courtship purposes.[38][39] It has been observed that call rates tend to increase during the breeding period and decrease during the incubation period.[39][40] Corfield’s work[38] has suggested that North Island brown kiwi vocalisation is suited for short-range calls to close-by individuals and territory neighbours.

There are notable differences between the two sexes' vocalisations. Male North Island brown kiwi calls produce high-pitched (≤36) multi-harmonic notes, whereas females typically emit low-frequency notes.[38] These differences are attributed to differences in the structure and size of their sound producing throat organs.[38] Additionally, males have been observed to have a significantly higher call rate compared to females.[40]

Conservation

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The North Island brown kiwi is Vulnerable, per the IUCN Red List,[1] with the major threat coming from predators, such as dogs, cats, and stoat (Mustela erminea). 94% of chicks die before breeding in areas where mammalian pest control is not carried out.[2] It has an occurrence range of 38,400 km2 (14,800 sq mi), with a population, estimated in 2000, of 35,000.[2]

In 1996 there were around 35,000 North Island brown kiwi and in 2006 there were 20,000.[25]

Nationwide studies show that on average only 5 percent of kiwi chicks survive to adulthood. However, in areas under active pest management, survival rates for North Island brown kiwi can be far higher. For example, prior to a joint 1080 poison operation undertaken by DOC and the Animal Health Board in Tongariro Forest in 2006, 32 kiwi chicks were radio-tagged. 57% of the radio-tagged chicks survived to adulthood. Thanks to ongoing pest control, the adult kiwi population at Tongariro has almost doubled since 1998.[citation needed]

In 2006, kiwi were released into Remutaka Forest Park by the Remutaka Conservation Trusts. As of 2024, the population has reached 300 individuals in the park and surrounding areas, extending to Upper Hutt and Whitemans Valley.[41]

In 2022, 11 North Island brown kiwi were released on Wellington's South Coast after a 100 year absence.[42] Fifty more kiwi were released into the hills of Wellington in May 2023.[43]

References

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  1. ^ a b BirdLife International (2017). "Apteryx mantelli". IUCN Red List of Threatened Species. 2017: e.T45353580A119177586. doi:10.2305/IUCN.UK.2017-3.RLTS.T45353580A119177586.en. Retrieved 18 November 2021.
  2. ^ a b c d e f "Northern Brown Kiwi Apteryx mantelli". BirdLife International. Archived from the original on 29 November 2008.
  3. ^ Gill; et al. (2010). "Checklist of the birds of New Zealand, Norfolk and Macquarie Islands, and the Ross Dependency, Antarctica" (PDF) (4th ed.). Te Papa Press. Retrieved 22 May 2016.
  4. ^ Ümüt Çınar (2015). "01 Pᴀʟᴇᴏɢɴᴀᴛʜᴀᴇ : Sᴛʀᴜᴛʜɪᴏɴɪfᴏʀᴍᴇs, Rʜᴇɪfᴏʀᴍᴇs, Cᴀsᴜᴀʀɪɪfᴏʀᴍᴇs, Aᴘᴛᴇʀʏɢɪfᴏʀᴍᴇs, Aᴇᴘʏᴏʀɴɪᴛʜɪfᴏʀᴍᴇs, Dɪɴᴏʀɴɪᴛʜɪfᴏʀᴍᴇs, Lɪᴛʜᴏʀɴɪᴛʜɪfᴏʀᴍᴇs, Tɪɴᴀᴍɪfᴏʀᴍᴇs & Rᴇfᴇʀᴇɴᴄᴇs". Retrieved 8 August 2016.
  5. ^ "A History of the Birds of New Zealand". Victoria University of Wellington.
  6. ^ Records, Guinness World (2013). Guinness World Records (Hardcover ed.). Guinness World Records. p. 50. ISBN 9781904994879.
  7. ^ Le Duc, Diana; Renaud, Gabriel; Krishnan, Arunkumar; Almén, Markus Sällman; Huynen, Leon; Prohaska, Sonja J.; Ongyerth, Matthias; Bitarello, Bárbara D.; Schiöth, Helgi B.; Hofreiter, Michael; Stadler, Peter F. (23 July 2015). "Kiwi genome provides insights into evolution of a nocturnal lifestyle". Genome Biology. 16 (1): 147. doi:10.1186/s13059-015-0711-4. hdl:11858/00-001M-0000-0028-1FE4-8. ISSN 1465-6906. PMC 4511969. PMID 26201466. S2CID 3156484.
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  9. ^ McLennan, J.A.; Miles, J.; Gillingham, N.; Waiwai, R. (2004). Size matters: Predation risk and juvenile growth in North Island brown kiwi (Apteryx mantelli). New Zealand Journal of Ecology. 28: 241-250. (newzealandecology.org)
  10. ^ Miles, J.R.G.; Potter, M.A.; Fordham, R.A. (1997). "Northern brown kiwi (Apteryx australis mantelli) in Tongariro National Park and Tongariro Forest – ecology and threats." Science for conservation: 51, Department of Conservation, Wellington, New Zealand, 23 pp
  11. ^ Davies, S.J.J.F. (2003). "Kiwis". In Hutchins, Michael (ed.). Grzimek's Animal Life Encyclopedia. Vol. 8 (2nd ed.). Farmington Hills, MI: Gale Group. pp. 89–92. ISBN 0-7876-5784-0.
  12. ^ Apteryx mantelli in Field Guide: Birds of the World on Flickr
  13. ^ Baker, A.J.; Daugherty, C.H.; Colbourne, R.; McLennan, J.L. (1995). "Flightless brown kiwis of New Zealand possess extremely subdivided population structure and cryptic species like small mammals". Proceedings of the National Academy of Sciences. 92 (18): 8254–8258. Bibcode:1995PNAS...92.8254B. doi:10.1073/pnas.92.18.8254. ISSN 0027-8424. PMC 41135. PMID 7667277.
  14. ^ a b Burbidge, Maryann L.; Colbourne, Rogan M.; Robertson, Hugh A.; Baker, Allan J. (2003). "Molecular and other biological evidence supports the recognition of at least three species of brown kiwi". Conservation Genetics. 4 (2): 167–177. Bibcode:2003ConG....4..167B. doi:10.1023/A:1023386506067. ISSN 1572-9737.
  15. ^ Tennyson A.J.D.; Palma R.L.; Robertson H.A.; Worthy T.H.; Gill B.J. (2003). A new species of kiwi (Aves, Apterygiformes) from Okarito. N Z Rec Auckland Mus.40: 55–64
  16. ^ "Massey News Article - do ya think I'm sexy?" (Press release). Archived from the original on 18 February 2007. Retrieved 26 September 2007.
  17. ^ a b c Save the Kiwi (2008). "Population status of the North Island Brown Kiwi". Save the Kiwi. Archived from the original on 26 May 2009. Retrieved 9 July 2009.
  18. ^ Mike Lee (5 February 2024). "Letter to the editor Gulf News".
  19. ^ "BirdLife Species Factsheet".
  20. ^ "Brown kiwi". www.doc.govt.nz. Retrieved 15 October 2024.
  21. ^ a b c d e f g Taborsky, Barbara.; Taborsky, Michael. (1995). "Habitat Use and Selectivity by the Brown Kiwi (Apteryx australis mantelli) in a Patchy Environment". The Auk. 112 (3): 680–689. ISSN 0004-8038. JSTOR 4088683.
  22. ^ a b c Butler, D.; McLennan, J. (n.d.). Kiwi Recovery Plan. Department of Conservation. https://www.doc.govt.nz/globalassets/documents/science-and-technical/tsrp02.pdf
  23. ^ Jamieson, Sarah E.; Castro, Isabel; Jensen, Thomas; Morrison, Kyle W.; Durrant, Barbara. (2016). "Roosting Preferences of North Island Brown Kiwis (apteryx Mantelli)". The Wilson Journal of Ornithology. 128 (4): 857–866. doi:10.1676/15-064.1. ISSN 1559-4491. JSTOR 26429952.
  24. ^ Miller, P.; Pierce, Ray. (1995). Distribution and decline of the North Island brown kiwi (Apteryx australis mantelli) in Northland. Notornis. 42. https://www.birdsnz.org.nz/wp-content/uploads/2021/12/Notornis_42_3_203.pdf
  25. ^ a b c Sales, James. (2005). "The endangered kiwi: a review". Folia Zool. 54 (1): 20.
  26. ^ a b c d Martin, Graham R.; Wilson, Kerry-Jayne.; Wild, J. Martin.; Parsons, Stuart.; Kubke, M. Fabiana.; Corfield, Jeremy. (2007). "Kiwi Forego Vision in the Guidance of Their Nocturnal Activities". PLOS ONE. 2 (2): e198. Bibcode:2007PLoSO...2..198M. doi:10.1371/journal.pone.0000198. ISSN 1932-6203. PMC 1805817. PMID 17332846.
  27. ^ a b Cunningham, Susan J.; Corfield, Jeremy R.; Iwaniuk, Andrew N.; Castro, Isabel; Alley, Maurice R.; Birkhead, Tim R.; Parsons, Stuart. (2013). "The Anatomy of the bill Tip of Kiwi and Associated Somatosensory Regions of the Brain: Comparisons with Shorebirds". PLOS ONE. 8 (11): e80036. Bibcode:2013PLoSO...880036C. doi:10.1371/journal.pone.0080036. ISSN 1932-6203. PMC 3828210. PMID 24244601.
  28. ^ a b c Cunningham, Susan.; Castro, Isabel.; Alley, Maurice. (2007). "A new prey-detection mechanism for kiwi ( Apteryx spp.) suggests convergent evolution between paleognathous and neognathous birds". Journal of Anatomy. 211 (4): 493–502. doi:10.1111/j.1469-7580.2007.00786.x. ISSN 0021-8782. PMC 2375824. PMID 17711422.
  29. ^ a b Cunningham, Susan J.; Castro, Isabel.; Potter, Murray A. (2009). "The relative importance of olfaction and remote touch in prey detection by North Island brown kiwis". Animal Behaviour. 78 (4): 899–905. doi:10.1016/j.anbehav.2009.07.015. ISSN 0003-3472.
  30. ^ a b c d e Taborsky, Barbara.; Taborsky, Michael. (1991). "Social Organization of North Island Brown Kiwi: Long-term Pairs and Three Types of Male Spacing Behaviour". Ethology. 89 (1): 47–62. Bibcode:1991Ethol..89...47T. doi:10.1111/j.1439-0310.1991.tb00292.x. ISSN 0179-1613.
  31. ^ a b Taborsky, Barbara; Taborsky, Michael. (1999). "The Mating System and Stability of Pairs in Kiwi Apteryx spp". Journal of Avian Biology. 30 (2): 143–151. doi:10.2307/3677123. ISSN 0908-8857. JSTOR 3677123.
  32. ^ a b Jolly, J.N. (1989). "A field study of the breeding biology of the little spotted kiwi ( Apteryx owenii ) with emphasis on the causes of nest failures". Journal of the Royal Society of New Zealand. 19 (4): 433–448. Bibcode:1989JRSNZ..19..433J. doi:10.1080/03036758.1989.10421846. ISSN 0303-6758.
  33. ^ a b c Reid, Brian; Williams, G.R. (1975), Kuschel, G. (ed.), "The Kiwi", Biogeography and Ecology in New Zealand, Dordrecht: Springer Netherlands, pp. 301–330, doi:10.1007/978-94-010-1941-5_7, ISBN 978-94-010-1941-5, retrieved 15 October 2024
  34. ^ a b c d McLENNAN, J.A. (1988). "Breeding of North Island Brown Kiwi, Apteryx Australis Mantelli, in Hawke's Bay, New Zealand". New Zealand Journal of Ecology. 11: 89–97. ISSN 0110-6465. JSTOR 24052821.
  35. ^ a b c d e Colbourne, Rogan. (2002). "Incubation behaviour and egg physiology of kiwi (Apteryx spp.) in natural habitats". New Zealand Journal of Ecology. 26 (2): 129–138. ISSN 0110-6465. JSTOR 24055315.
  36. ^ McLennan, J.A.; McCann, A.J. (1991). ""Incubation Temperatures of Great Spotted Kiwi, Apteryx haastii"" (PDF). New Zealand Journal of Ecology. 15 (2): 163–166.
  37. ^ a b Bain, I, A. (2018). Egg-size variation in North Island brown kiwi (Apteryx mantelli): influences and consequences [Masters Thesis, University of Canterbury]. UC Research Repository. https://ir.canterbury.ac.nz/server/api/core/bitstreams/70b0fafb-a558-4897-b472-81c604d1f72d/content
  38. ^ a b c d e f Corfield, Jeremy.; Gillman, Len.; Parsons, Stuart. (2008). "Vocalizations of the North Island Brown Kiwi (Apteryx mantelli)". The Auk. 125 (2): 326–335. doi:10.1525/auk.2008.06234. ISSN 0004-8038.
  39. ^ a b c Taborsky, Barbara.; Taborsky, Michael. (1992). "Spatial organization of the North Island Brown Kiwi Apteryx australis mantelli: sex, pairing status and territoriality". Ibis. 134 (1): 1–10. doi:10.1111/j.1474-919X.1992.tb07222.x. ISSN 0019-1019.
  40. ^ a b Colbourne, R.; Digby, A. (2016). Call rate behaviour of brown kiwi (Apteryx mantelli) and great spotted kiwi (A. haastii) in relation to temporal and environmental parameters: DOC RESEARCH AND DEVELOPMENT SERIES 348. Department of Conservation. https://www.doc.govt.nz/documents/science-and-technical/drds348entire.pdf
  41. ^ "Watch: Kiwi spreading from Remutaka Ranges to Upper Hutt". RNZ. 16 July 2024.
  42. ^ "Brown kiwi released on Wellington's southwest coast". RNZ. 22 November 2022. Retrieved 8 May 2023.
  43. ^ "Fifty kiwi set to be released into the hills of Wellington". RNZ. 9 May 2023. Retrieved 8 May 2023.

Further reading

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  • Davies, S.J.J.F. (2003). "Kiwis". In Hutchins, Michael (ed.). Grzimek's Animal Life Encyclopedia. Vol. 8 Birds I Tinamous and Ratites to Hoatzins (2nd ed.). Farmington Hills, MI: Gale Group. pp. 89–92. ISBN 978-0-7876-5784-0.
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