Black stilt/kaki
Image: Sabine Bernert ©

Introduction

Kakī, or black stilt, is a native wading bird that is critically endangered. They have been intensively managed since 1981, when their population declined to a low of just 23 birds.

Highlights

Population: 55 wild birds in 2005
Conservation status: Nationally Critical (2012)
Found in: Braided rivers and wetlands of the Mackenzie Basin, South Island
Threats: Predators, habitat loss, disturbance

In this section

Did you know

Kaki, or black stilt (Himantopus novaezelandiae), is a native wading bird only found in New Zealand. It is regarded by Maori as a taonga species – a living treasure. Once common throughout New Zealand, kaki is now restricted to the braided rivers and wetlands of the Mackenzie Basin, South Island. Kaki are critically endangered.

Kaki have completely black plumage and long red legs. Young kaki have black and white plumage until 18 months old, when they become all black.

Black stilt/kaki. Photo © Sabine Bernert.
Kaki first breed when aged two or three years, and are known to mate for life

Black stilt/kaki. Photo © Sabine Bernert.
Black stilt/kaki is a native wading bird only found in New Zealand

Kaki are found in braided riverbeds, side streams, swamps and tarns and sometimes on lake margins and irrigated paddocks if there is good feed available. Most riverbed birds migrate to the coast in winter, but kaki usually continue to feed on the parts of river and delta which do not freeze over.

Kaki are opportunistic feeders, mostly taking aquatic insects, molluscs and small fish. They can wade out into deeper, slower moving water than most riverbed birds, reaching reach down to catch insects, such as mayfly and caddisfly larvae, on the river bottom. Sometimes they dart at insects and small fish in shallow rapids or muddy areas.

Unlike pied stilts and other waders, they can also feed by using a scything motion with their bill.

Breeding and nesting

Kaki first breed when aged two or three years, and are known to mate for life. If they cannot find a kaki mate, they may sometimes breed with the pied stilt, a close relative.

Each pair of kaki defends a territory, and nest alone, on stable banks near the water in braided riverbeds, side streams and swamps.

They rely on camouflage to protect their eggs and chicks, and actively defend their nests. Incubation is shared equally by the parents and takes 25 days. Within hours, newly hatched chicks can hunt for food and swim if necessary.

Black stilt/kaki. Photo © Sabine Bernert.
You can help by following the river care code when you're at the Mackenzie Basin

Black stilt/kaki habitat. Photo © Sabine Bernert.
Once common throughout New Zealand, black stilt/kaki are now restricted to the braided rivers and wetlands of the Mackenzie Basin, South Canterbury

Sound recordings

Adult black stilt/kakī song (MP3, 2,380K) 
2 minute 36 second recording of territorial and alarm calls of two adult black stilt/kakī protecting their young

Note: Right-click the song link for options to save. Bird songs may be reused according to our copyright terms. More help on files.

Threats

At the time of European settlement, kaki were found in many of New Zealand’s rivers and wetlands. There was plenty of habitat and the risk of predation was low. As European settlement intensified, New Zealand’s environment began to change. Settlers introduced foreign plants and animals, drained wetlands for development, and channelised rivers.

With the spread of new predators and extensive modification of their habitat, by 1981 kaki numbers declined to a low of just 23 birds.

The main threats to kaki include:

  • Predators – especially introduced mammalian predators like feral cats and ferrets.
  • Habitat loss and modification – such as hydroelectric and agricultural development and weed invasion.
  • Human disturbance – recreational users of riverbeds and wetlands can crush eggs or chicks and scare adult kaki away from their nests.

The challenge now is to learn how and when to manage these threats. Targeted research will help to identify the most effective and efficient management techniques to use.

With the support of landowners, recreationalists and the general public, we hope that kaki will thrive in their natural habitat once more.

Kaki recovery programme

Kaki have been intensively managed since 1981, when their population declined to a low of just 23 birds. DOC’s captive breeding centre, near the town of Twizel in the Mackenzie Basin, plays an important role in the Kaki Recovery Programme.

DOC staff with black stilt/kaki. Photo © Sabine Bernert.
DOC staff with black stilt/kaki

Releasing black stilt/kaki. Photo © Sabine Bernert.
Releasing black stilt/kaki

A number of kaki pairs are held at the centre for captive breeding. All kaki eggs are artificially incubated and the young chicks are raised in captivity. At 2–9 months they are released into the wild. Rearing them in captivity significantly increases their chances of survival by preventing predation when they are most vulnerable, (as chicks and eggs).

Twizel Area School made trap boxes for the kaki project. Image: K.Mckinley.
Students of Twizel Area School made boxes for predator traps, to help kaki

Conservation efforts to date have succeeded in averting extinction and increasing kaki numbers. By 2005, kaki numbers in the wild had increased to 55 adults, including 11 pairs. The next phase of the recovery programme will address the complex issues associated with managing kaki in the wild.

Black stilt/kaki. Photo © Sabine Bernert.
With the support of landowners, recreationalists and the general public, we hope that kaki will thrive in their natural habitat once more

You can help

  • Follow the river care code when visiting the riverbeds of the Mackenzie Basin:
    • River birds nest on the ground. Their eggs and chicks are almost impossible to spot from a vehicle. Do not drive in riverbeds from August to December.
    • Birds swooping, circling or calling loudly probably have nests nearby. Move away so they can return to them, or their eggs and chicks could die.
    • A dog running loose can wreak havoc. Leave your dog at home or keep it under strict control.
    • Jet boats disturb birds and can wash away nests near the water’s edge. The speed limit for boats is 5 knots within 200 m of the bank.
  • Watch The Black Silt documentary on NZ on Screen
  • Keep updated on the Kaki Recovery Programme on their Facebook page

Help protect New Zealand's native birds

  • Volunteer with DOC or other groups to control predators and restore bird habitats.
  • Don’t throw rubbish into water ways or storm drains.
  • Set traps for stoats or rats on your property. Get more information from your local DOC office.
  • Put a bell on your cat's collar, feed it well, and keep it indoors at night.
  • Plant a range of native plants that provide food year-round to encourage birds into your garden.
When visiting parks and beaches
  • Only take dogs to areas that allow them, and keep your dog under control.
  • Prevent the spread of pests. Check your gear for mice and rats when visiting pest-free islands.
  • Use available access ways to get to the beach. Stay out of fenced-off areas. Leave nesting shore birds alone.
  • Get your dog trained in avian awareness, and help save forest birds like kiwi and weka.
  • Follow the water care code. Keep water craft speed to 5 knots within 200 metres of the shore.
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