Southern brown kiwi

Southern brown kiwi
Stewart Island tokoeka
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Apterygiformes
Family: Apterygidae
Genus: Apteryx
Species: A. australis
Binomial name
Apteryx australis
Shaw 1813[2]
Sub-species

A. a. lawryi (Rothschild, 1893) Checklist Committee 1953[3]
Stewart Island tokoeka
A. a. australis Shaw 1813[3]
Haast tokoeka

The distribution of southern brown kiwi
Synonyms
  • A. a. lawryi (Rothschild 1893) Checklist Committee 1953[4]
    • Apteryx maxima Buller 1891 non Hutton 1871
    • Apteryx lawryi Rothschild 1893
  • A. a. australis Shaw 1813

The southern brown kiwi, tokoeka, or common kiwi,[2] Apteryx australis, is a species of kiwi from New Zealand's South Island. Until 2000 it was considered conspecific with the North Island brown kiwi, and still is by some authorities.

Taxonomy

Apteryx australis is based on Greek and Latin. Apteryx means "A-" without "pterux" wings, and "australis" from "auster" the south wind, and "-alis" relating to. Hence relating to the south wind is the meaning of australis, not Australia.[5] The southern brown kiwi belongs to the kiwi family and it is a ratite, and a member of the order Struthioniformes. Like all ratites, its sternum has no keel, it is flightless, and it has a distinctive palate.[2]

The southern brown kiwi is divided into two subspecies:

Description

Dissected specimen, with exposed muscles and wing-claw

It has no preen gland, and its feathers have no aftershafts and no barbules. There are large vibrissae around its gape, and it has no tail, only a pygostyle. It has a length of 45 to 55 cm (18–22 in) and the female weighs 2.1 to 3.9 kg (4.6–8.6 lb) and the male weighs 1.6 to 2.8 kg (3.5–6.2 lb). Its bill is long and slender with a slight down-curve. Like other kiwis it is nocturnal. The colour of its plumage is rufous with some streaking.[2]

Behaviour

Vocalisation

Southern brown kiwi communicate vocally to aid in defending their territory. They will also sing duets with each other, with the male shrill "kee-wee" or "kee-kee" and the females hoarse " kurr kurr".[7] Males are more vocal and they both call in an upright position with their legs stretched out and their bill pointing up.[2]

Diet

Specimen foraging on Stewart Island

The southern brown kiwi has a long slender bill with lateral nostrils at the tip, which helps give them their keen sense of smell. They utilise this, more than sight and sound, to forage in dirt for invertebrates, including earthworms, beetle larvae, snails, spiders, centipedes, and orthoptera. Its gizzard is weak, and underutilised due to the lack of plant matter. Its caeca are long and narrow and aid in digestion.[2]

Reproduction

Skeleton

The southern brown kiwi, like all kiwi, has two functioning ovaries, however only the left oviduct functions, allowing eggs from both ovaries to pass through. It is a monogamous species and once paired up, they will defend their territories with warning calls. The size of their territory is between 4.9 and 43 hectares (12 and 106 acres). Nests are made in burrows, or sheltered beneath thick vegetation. The female lays 1–2 eggs, typically just 1, which the male incubates for 90 days. After a few days the chick will exit the nest and feed on its own, although it may stay around parents for a year. When not incubating eggs, they roost alone in sheltered places at ground level.[2]

Range and habitat

Breeding Population and Trends[6]
Location Population Date Trend
Stewart Island 20,000 1996 Stable
Fiordland 7,000 1996 Decreasing
Haast 300[8] 2008 Increasing
Total (New Zealand) 27,000 1996 Declining

Southern brown kiwi live in the South Island and Stewart Island. On the mainland (South Island) they live in Fiordland and Westland. Their range is temperate and sub-tropical forests, grassland, and shrubland, the denser the better.[2] They are widespread throughout Stewart Island where they also live on the sand dunes.[6]

Conservation

In 2000, after being recognised by IUCN, they were placed in the Vulnerable status group.[1] They have an occurrence range of 9,800 km2 (3,800 sq mi) and population of 27,000 was estimated in 1996.[6] Brush-tailed possums, Trichosurus vulpecula, and stoats, Mustela erminea, will eat the eggs, while stoats and cats will eat chicks and juveniles. Adults are also under threat as dogs, ferrets, and brush-tailed possums, attack them and the juveniles. The Stewart Island population is stable due to the lack of these predators,[1] however stoats may have colonised the island in 2000.[6]

Footnotes

  1. 1 2 3 BirdLife International (2013). "Apteryx australis". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
  2. 1 2 3 4 5 6 7 8 Davies, S. J. J. F. (2003)
  3. 1 2 Brands, S. (2008)
  4. ↑ 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.
  5. ↑ Gotch, A. F. (1995)
  6. 1 2 3 4 5 6 BirdLife International (2016)
  7. ↑ "Southern brown kiwi". May 2014.
  8. ↑ Save the Kiwi (2008)

References

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