Southern Brown Kiwi (Apteryx australis)

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Image of a Southern brown kiwi
Birds Kiwi

Introduction

The Southern Brown Kiwi, also known as tokoeka, is a flightless New Zealand bird with the scientific name Apteryx australis. It is endemic to the southern South Island, Fiordland, the Haast region and Rakiura, also known as Stewart Island. Like other kiwi, it is a ground-dwelling bird with a highly developed sense of smell, a long bill and loose, hair-like feathers. It is an important national symbol and a taonga of significance to Māori. (doc.govt.nz)

Physical Description

The Southern Brown Kiwi is a stout, pear-shaped bird that stands about 45 centimetres tall. Males weigh approximately 2.4 kilograms, while females are heavier at about 3.1 kilograms and have longer bills. The plumage ranges from rufous brown in Haast birds to darker brown elsewhere, with lengthwise streaks of reddish brown and black. The feather tips are soft and hair-like, giving the bird a shaggy appearance.

It has tiny vestigial wings, no visible tail and short, powerful legs with strong claws. The long, pale bill is slightly curved and has nostrils near the tip, an unusual feature among birds. Sensitive structures at the bill tip help the kiwi detect prey beneath leaf litter and soil. Its small eyes, large ears and well-developed sense of smell reflect its adaptation to life on the forest floor. (doc.govt.nz)

Young kiwi hatch fully feathered and are active soon after leaving the nest. They differ from adults mainly in size and plumage development, rather than having a strongly contrasting juvenile colour pattern. Juveniles grow slowly and may remain associated with their parents for an extended period, depending on the population and local conditions. (doc.govt.nz)

Range and Habitat

The Southern Brown Kiwi is endemic to New Zealand. It occurs in parts of the south-western South Island, including Fiordland and the Haast region, and on Rakiura, or Stewart Island, together with some nearby islands such as Ulva Island. Its range is now more restricted and fragmented than it was before widespread habitat modification and the arrival of introduced predators.

Tokoeka use native forest, scrub, tussock grassland and subalpine habitats. They may occur from coastal areas to mountainous terrain, using burrows, rock crevices, hollow logs and spaces beneath tree roots for shelter and nesting. The species includes several geographically distinct forms, including Haast, northern Fiordland, southern Fiordland and Rakiura tokoeka. These forms differ in appearance, genetics, behaviour and conservation needs, and are managed separately in some conservation programmes. (doc.govt.nz)

The species is resident rather than migratory. Most individuals remain within a familiar home range, although young birds may disperse short distances before establishing their own territories.

Behaviour and Diet

Southern Brown Kiwis are generally nocturnal and secretive. They use their strong legs and bills to probe soil, leaf litter, moss and rotting wood. Their diet includes earthworms, insect larvae, beetles, spiders and other invertebrates, as well as some fruit and seeds. Smell, hearing and sensitive bill-tip structures are important when locating prey in dark or concealed places. (doc.govt.nz)

Most tokoeka are active at night, although Rakiura birds are unusually likely to forage during the day, particularly in suitable weather and quiet locations. Pairs are generally monogamous and defend territories with repeated calls. The male’s call is a high-pitched, ascending whistle, while the female gives a deeper, hoarse call.

Breeding can occur through much of the year, with activity commonly recorded from July to March. The female normally lays one very large, pale green egg. The egg may represent approximately 15 to 20 per cent of her body weight. Incubation lasts about 70 to 80 days. The male usually performs most of the incubation, although the female may relieve him for periods, and some southern populations show more shared incubation. Chicks hatch fully feathered, leave the nest after several days and begin feeding independently rather than being fed by their parents. (blog.doc.govt.nz)

Identification Tips

Look for the following combination of features:

  • A large, rounded, flightless bird with no visible tail.
  • Soft, shaggy plumage that is rufous brown, brown or dark brown and streaked lengthwise.
  • A long, pale, slightly curved bill with nostrils close to the tip.
  • Short, strong legs and large claws.
  • A mainly nocturnal and ground-dwelling lifestyle.
  • Loud territorial calls, often heard before the bird is seen.

Southern Brown Kiwi can be confused with weka because both are flightless, ground-dwelling New Zealand birds. Kiwi are more rounded, have a much longer bill and lack the obvious tail seen on weka. Rowi are generally smaller and greyer, while Southern Brown Kiwi are typically larger and more strongly brown or rufous. (nzbirdsonline.org.nz)

Conservation Status

The Southern Brown Kiwi is listed nationally in New Zealand as Naturally Uncommon, but conservation status varies among its geographically distinct forms. Haast and Fiordland tokoeka are threatened, while Rakiura tokoeka is classified as At Risk, Naturally Uncommon, under New Zealand’s national system. (doc.govt.nz)

The principal threats are predation by introduced stoats, dogs, feral cats and other introduced mammals, together with habitat modification, vehicle strikes and the vulnerability of small, isolated populations. Stoats are especially damaging to chicks, while dogs can kill adult kiwi. Without predator control, survival to adulthood can be very low in some populations. (doc.govt.nz)

Conservation measures include predator trapping, aerial pest control in selected areas, habitat protection, population monitoring, translocations and captive incubation. Operation Nest Egg removes selected eggs from the wild so that chicks can hatch and grow in safer conditions before being returned to protected habitat. Predator control and partnerships involving the Department of Conservation, iwi, community groups and conservation organisations are important to the recovery of local populations. (doc.govt.nz)

Frequently Asked Questions

Where does the Southern Brown Kiwi live?

It lives in parts of the southern South Island, including Fiordland and the Haast region, and on Rakiura, or Stewart Island, together with some nearby islands.

Is the Southern Brown Kiwi nocturnal?

Usually. Most Southern Brown Kiwi forage at night, although Rakiura tokoeka are more often active during the day than other forms.

What does the Southern Brown Kiwi eat?

Its diet consists mainly of earthworms, insects, larvae, spiders and other invertebrates. It also eats some fruit and seeds.

How can the Southern Brown Kiwi find food underground?

It uses smell, hearing and sensitive structures near the tip of its bill to locate prey in soil, leaf litter, moss and rotting wood.

How many eggs does a Southern Brown Kiwi lay?

The female normally lays one very large, pale green egg. Incubation lasts about 70 to 80 days, with the male usually doing most of the incubation.

Why is the Southern Brown Kiwi threatened?

Introduced predators, especially stoats and dogs, kill chicks and adults. Habitat modification, vehicle strikes and the small size of some isolated populations also increase its vulnerability.

References

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