T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Kiwi (Apteryx genus)

Kingdom:   Animalia
Phylum:     Chordata
Class:        Aves
Clade:       Novaeratitae
Order:       Apterygiformes
Family:      Apterygidae
Genus:      Apteryx
Species:
Apteryx mantelli, North Island brown kiwi
Apteryx haastii, Great spotted kiwi
Apteryx owenii, Little spotted kiwi
Apteryx rowi, Okarito brown kiwi
Apteryx australis, Southern brown kiwi (3 sub species)

Kiwis are shy, nocturnal, flightless birds native to New Zealand. The kiwi is a national symbol of New Zealand, and the association is so strong that the term Kiwi is used internationally as the colloquial demonym for New Zealanders.
 

An adult bird is about the size of a domestic chicken. Kiwi are the smallest living ratites (which also consist of ostriches, emus, rheas, and cassowaries), and lay the largest egg in relation to their body size of any species of bird in the world. Kiwi eggs can weigh up to one-quarter the weight of the female. Male and female kiwis tend to live their entire lives as a monogamous couple. The male always incubates the egg, except for the Great Spotted Kiwi, A. haastii, in which both parents are involved. The incubation period is 63–92 days. After hatching the young bird will usually stay close to the male. After about a month it will move off to live indenpendenly, but may stay within itd parents territory for the first year.
Kiwis 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. Kiwis 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 using their keen sense of smell, without actually seeing or feeling them. Kiwi sometimes sound like pigs, snuffling and snorting loudly to clear dirt from their nostrils.

There are five recognised species, two of which are currently vulnerable, one of which is endangered, and one of which is critically endangered. All species have been negatively affected by historic deforestation but currently the remaining 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 5 Kiwi Species are:

  The North Island brown kiwi, Apteryx mantelli 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 With North Island brown kiwi the female lays the eggs while the male has responsibility for them during the 85 days of incubation.

 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.

3   The 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 KapitiIsland 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.

4   The Okarito 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 this kiwi is limited to a small area on the west coast of the South Island of New Zealand. 

 The southern brown kiwi, Apteryx australis is a relatively common species of kiwi known from south and west parts of the South Island that occurs at most elevations. There are several subspecies of the Tokoeka recognised:
a; The Stewart Island southern brown kiwi, Apteryx australis lawryi, is a subspecies of Tokoeka from Stewart Island/Rakiura
b; 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.
c: The Haast southern brown kiwi, Haast tokoeka, Apteryx australis ‘Haast’, is the rarest subspecies of kiwi with only about 300 individuals. It occurs only in a restricted area in the South Island's HaastRange of the Southern Alps at an altitude of 1,500 m.

New Zealand Kiwi Map (Courtesy of Grutness , Wikipedia modified by Tony Wills


A male Northern Brown Kiwi (Apteryx mantelli)
Photo courtesy of Maungatautari Ecological Island Trust   http://www.maungatrust.org/      Photo by Kahuroa, Wikipedia photo.
   

A kiwi skeleton showing the size of the egg in relation to the mothers body.


Radio-telemetry is considered the best tool for locating kiwi so their survival and movement can be monitored, and it is used as the primary tool to find nests and follow their fate. Most kiwi radio-tracking are ground-based; however, some kiwi, especially juveniles and sub-adults, can wander long distances (20+ km), and the only effective way to find them is to use aircraft to detect the signals from the transmitters attached to them.

Tracking a kiwi by radio


After locating a male is removed for a nest for his health check.


A kiwi in the arms of a Kiwi researcher.


A kiwi strong legs and powerful claws used to dig in the forest floor seaching for food.


A young kiwi breaking open its egg.  The young female kiwi was knicknamed "Rock Star" as the news that she hatch in a car made world news


Rockstar having a transmitter fitted to her leg six moths after hatching.


A radio transmitter on a kiwi's leg.


A video on the kiwi produced by 'Kiwis for kiwi' which is a fundraising and advocacy organisation working to support the conservation of kiwi and the places they live. Please visit our website http://www.kiwisforkiwi.org/ to learn more and see how you can help save the kiwi conservation.
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