The Okarito kiwi (''Apteryx rowi''), also known as the rowi or Okarito brown kiwi, is a member of the

kiwi Kiwi most commonly refers to: * Kiwi (bird), a flightless bird native to New Zealand * Kiwi (nickname), a nickname for New Zealanders * Kiwifruit, an edible berry * Kiwi dollar or New Zealand dollar, a unit of currency Kiwi or KIWI may also refe ...

family Apterygidae, described as new to science in 2003. The species is part of the brown kiwi complex, and is morphologically very similar to other members of that complex. It is found in a restricted area of the

Ōkārito Ōkārito is a small coastal settlement on the West Coast of New Zealand's South Island, southwest of Hokitika, and from . It is built at the southern end of the Ōkārito Lagoon at the mouth of the Ōkārito River. The settlement of The Fo ...

forest on the

West Coast West Coast or west coast may refer to: Geography Australia * Western Australia *Regions of South Australia#Weather forecasting, West Coast of South Australia * West Coast, Tasmania **West Coast Range, mountain range in the region Canada * Britis ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

, and has a population of only about 600 birds.

Taxonomy

The Okarito kiwi is a monotypic species, i.e. there are no recognised subspecies. The genus name '' Apteryx'' stems from the Greek "without wings". Originally assumed to be the same species as the

Southern brown kiwi The southern brown kiwi, tokoeka, or common kiwiDavies, S. J. J. F. (2003) (''Apteryx australis'') is a species of kiwi from South Island, New Zealand. Until 2000 it was considered conspecific with the North Island brown kiwi, and still is by ...

''A. australis'', DNA testing shows that the possible split off from this species was 8.2 million years ago, and the split from their closest relatives, the Northern Island brown kiwi '' A. mantelli'' was around 6.2 million years ago. This bird is a

ratite A ratite () is any of a diverse group of flightless, large, long-necked, and long-legged birds of the infraclass Palaeognathae. Kiwi, the exception, are much smaller and shorter-legged and are the only nocturnal extant ratites. The systematics ...

and has similarities to the others (

emu The emu () (''Dromaius novaehollandiae'') is the second-tallest living bird after its ratite relative the ostrich. It is endemic to Australia where it is the largest native bird and the only extant member of the genus ''Dromaius''. The emu' ...

ostrich Ostriches are large flightless birds of the genus ''Struthio'' in the order Struthioniformes, part of the infra-class Palaeognathae, a diverse group of flightless birds also known as ratites that includes the emus, rheas, and kiwis. There are ...

, rhea,

cassowary Cassowaries ( tpi, muruk, id, kasuari) are flightless birds of the genus ''Casuarius'' in the order Casuariiformes. They are classified as ratites (flightless birds without a keel on their sternum bones) and are native to the tropical forest ...

). Its

sternum The sternum or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major blood vessels from injury. Sh ...

has no keel, its wings are minimal, and it has no

preen gland The uropygial gland, informally known as the preen gland or the oil gland, is a bilobed sebaceous gland possessed by the majority of birds used to distribute the gland's oil through the plumage by means of preening. It is located dorsally at the ...

. Its

palate The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly sepa ...

is also distinctive, and its feathers have no

barbule Feathers are epidermal growths that form a distinctive outer covering, or plumage, on both avian (bird) and some non-avian dinosaurs and other archosaurs. They are the most complex integumentary structures found in vertebrates and a premier ...

s or aftershaft. Other features that are similar to only the other

is a weak

gizzard The gizzard, also referred to as the ventriculus, gastric mill, and gigerium, is an organ found in the digestive tract of some animals, including archosaurs (pterosaurs, crocodiles, alligators, dinosaurs, birds), earthworms, some gastropods, so ...

and no tail, only a

pygostyle Pygostyle describes a skeletal condition in which the final few caudal vertebrae are fused into a single ossification, supporting the tail feathers and musculature. In modern birds, the rectrices attach to these. The pygostyle is the main compon ...

Range and habitat

The Okarito brown kiwi lives in the Okarito forest on the West Coast of New Zealand's South Island. On 29 June 2010, three breeding pairs were released onto

Blumine Island Blumine Island / is an island in the outer reaches of Queen Charlotte Sound / Tōtaranui, in the Marlborough Sounds at the northern end of New Zealand's South Island. The New Zealand Ministry for Culture and Heritage gives a translation of "mee ...

as part of a breeding programme. A new population was established in the Omoeroa Ranges near

Fox Glacier Fox Glacier (; officially Fox Glacier / Te Moeka o Tuawe) is a temperate maritime glacier located in Westland Tai Poutini National Park on the West Coast of New Zealand's South Island. Like nearby Franz Josef Glacier, Fox Glacier is one of th ...

in late 2018. In 2021 signs of Rowi were detected in Ballyhooly Bush, remnant mataī forest on the Lower Whataroa River flats, 24 km from Ōkārito forest.

Reproduction

The female can lay up to three

eggs Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especial ...

, each in a different

nest A nest is a structure built for certain animals to hold eggs or young. Although nests are most closely associated with birds, members of all classes of vertebrates and some invertebrates construct nests. They may be composed of organic materia ...

. Both the male and the female incubate the eggs. The egg is very large, as it weighs 20% of the female's weight (as in all kiwi). Most pairs are monogamous throughout their lives. TWC Wildlife Centre• Stewart Nimmo • MRD 8502

TWC Wildlife Centre• Stewart Nimmo • MRD 8502

Status and conservation

The Okarito kiwi is currently classified as Vulnerable by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

due to habitat loss and predation by introduced stoats. Conservation efforts such as Operation Nest Egg and the stoat control regime have been partially successful in restoring the rowi population. However, the rowi is still in a fragile stage of existence.

Predation Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

, mainly from imported animals such as

stoats The stoat (''Mustela erminea''), also known as the Eurasian ermine, Beringian ermine and ermine, is a mustelid native to Eurasia and the northern portions of North America. Because of its wide circumpolar distribution, it is listed as Least Conc ...

, is still the biggest threat to the rowi. The South Okarito Forest was designated a kiwi sanctuary in 2000. The

West Coast Wildlife Centre The West Coast Wildlife Centre is a kiwi-rearing facility in Franz Josef / Waiau, Franz Josef, New Zealand. A public-private partnership with the Department of Conservation (New Zealand), Department of Conservation and Te Rūnanga o Makaawhio, Te ...

in Franz Josef village operates a conservation programme as part of Operation Nest Egg. Eggs at risk of predation are removed, the chicks hatched in captivity, raised in a natural predator-free environment until old enough to fend for themselves, and then returned to the wild. The operation opened in 2010 and has been responsible for raising the wild population of rowi from just 165 ageing adults in the 1990s to 600 . Surveys have ensured that there is no noticeable difference in behaviour between such birds and rowi growing up fully in the wild. The Wildlife Centre is the only place in New Zealand where one can see rowi in a nocturnal walkthrough area.

References

External links

West Coast Wildlife Centre
{{Taxonbar, from=Q927358

Okarito kiwi The Okarito kiwi (''Apteryx rowi''), also known as the rowi or Okarito brown kiwi, is a member of the kiwi family Apterygidae, described as new to science in 2003. The species is part of the brown kiwi complex, and is morphologically very s ...

Birds of the South Island Ratites Flightless birds

Endemic birds of New Zealand