KIWI RECOVERY UNDERWAY

Forest and Bird, Volume 22, Issue 4, 1 November 1991, Page 27

KIWI RECOVERY UNDERWAY

Concerns for the future of kiwi have led the Department of Conservation to launch a Kiwi Recovery Programme in partnership with Forest and Bird and the Bank of New Zealand. This article summarises DoC’s Kiwi Recovery Plan and was compiled by Estelle Sarney.

MAGINE NEW ZEALAND without the kiwi. It’s unthinkable, but that tragedy has become possible. This unique bird, whose origins go back 70 million years, has become New Zealand's national symbol, yet few of the self-proclaimed human ‘kiwis’ have ever seen one in the wild or heard their call. Now the chances of such contact are becoming increasingly remote the kiwi is threatened with possible extinction. Scientists have noticed the forests becoming quieter. In many areas that used to ring at night with the shrill, quavering call of the kiwi the morepork now calls alone. We may have adopted the kiwi to represent ourselves, but we have also unwittingly triggered its decline. The kiwi is on the run in its own country from introduced predators and land clearance. Sometime in the past thirty years one of the three species of kiwi, the little spotted kiwi, became extinct on the mainland. It is a measure of how little we know about our national bird that the disappearance of this species went largely unnoticed. It is now exiled to Kapiti and other offshore islands, classified as not just threatened but endangered. The other two species, the great spotted

kiwi and the brown kiwi, and the three sub-species of brown kiwi, the North Island, South Island and Stewart Island varieties, are considered threatened. A five year kiwi recovery programme has been launched recently by the Department of Conservation. The recovery programme is a Threatened Species Trust project sponsored by the Bank of New Zealand in partnership with the Department of Conservation and the Royal Forest and Bird Protection Society. This recovery plan presents a five-year programme of research and management aimed at a long term goal of maintaining and, where possible, enhancing the current abundance, distribution and genetic diversity of kiwis. All kiwi species are included in this one plan because all are considered threatened with extinction unless the causes of declines are addressed. The little spotted kiwi is at particular risk and is classified as endangered. The establishment of populations on offshore islands and perhaps in captivity may continue to be necessary for those species in the most immediate danger, but this plan aims to retain kiwis on the mainland. It recognises that in the long run the best way of pre-

serving the diversity of New Zealand's flora and fauna is to conserve species as part of the community in which they have evolved.

Introducing the kiwi

Kiwi are the smallest members of the ratites, a group of flightless birds which includes the rheas of South America, the cassowaries of Australia and New Guinea, and the ostriches of Africa. They are endemic to New Zealand and ancient in origin; their ancestor, which may also have spawned the moas, probably arrived in New Zealand some 70 million years ago. Kiwis are biological oddities, unique in both appearance and behaviour. Many of their features are more typical of mammals than birds, with some scientists referring to them as New Zealand’s honorary mammals. Kiwis hold a variety of records among birds; their eggs are extremely large and rich in energy, and take an exceedingly long time to hatch. Males are the smaller of the two sexes and perform most of the parental care, which is unusual for a monogamous bird. The kiwi genus Apteryx is truly a "oneoff’ design, and it is not surprising, then, that kiwis have become an important part

of our culture, an unofficial national emblem proclaiming our uniqueness. They are, without question, among the most distinctive and interesting elements of our fauna.

Taxonomy

Three species of kiwi are recognised — the little spotted kiwi, the great spotted kiwi and the brown kiwi. The brown kiwi is also divided into three sub-species on the North Island, the South Island and Stewart Island. Research to be undertaken as part of the recovery plan will further define the taxonomy of kiwis, and changes to the status of the brown kiwi are likely.

Past and present distribution

Little Spotted Kiwi Members of this species used to be spread throughout the North Island but were all

but extinct there by the time the Europeans arrived. They used to be common in the South Island, but declined soon after the settlers arrived and are now probably extinct on both islands. They also occurred naturally on D’Urville Island, but are almost extinct there today. Today the little spotted kiwi is thought to exist only on offshore islands. The Kapiti Island population of between 500 and 1500 birds is the largest, and some have been shifted to Long Island in the Marlborough Sounds, Red Mercury Island off the Coromandel coast and Hen Island in the Hauraki Gulf. These new populations appear to be reasonably successful, but until they are more securely established the little spotted kiwi will be considered endangered. Great Spotted Kiwi This kiwi appears never to have reached the North Island, and to have contracted its range in the South Island over the past few hundred years. It is thought this species

was once more widespread east of the Southern Alps than they are now. The present distribution of great spotted kiwis is not known in detail. They are found in three fairly separate groups mainly west of the Alps, between the _ Whanganui Inlet just below Cape Farewell and the Karangarua River half way down the western side of the South Island. Brown Kiwi Brown kiwi densities which are considered exceptional today, such as that in Waipoua in Northland, seem to have been common in the North Island at the turn of the century. Large numbers were reported on Mt Hikurangi on East Cape, and in 1877 a group of hunters in the Kaimanawa Ranges southeast of Taupo were reported as having 300 skins in their possession, but kiwis are now seldom seen in those regions. It is thought that brown kiwis died out in the Tararua Ranges before the arrival of Europeans. Bones have been found at Paremata, north of Wellington, and in caves in the Wairarapa, but now the

southern most population in the North Island is at the tip of the Ruahine Range just south of the Hawke’s Bay. Their retreat northwards seems to be continuing. The brown kiwi was formerly widespread in Marlborough and the coastal regions of Kaikoura, Canterbury and northern Otago. Today the northernmost population in the South Island is at Okarito on the West Coast. The most successful population exists in Northland across a range of vegetation types including exotic forest and rough farmland. They extend south to a line running westwards from Mangawai Heads to the top of the Kaipara Harbour. Brown kiwis also live in the forests of the Coromandel Peninsula, in an area that fans out west from Lake Taupo to Kawhia Harbour southwest of Hamilton in the north and Wanganui in the south, and in an area east of Rotorua, extending from the Raukumara Ranges on East Cape to the tip of the Ruahine Range. The birds are often heard and caught in gin traps in the foothills along the eastern Bay of Plenty. Populations exist on Little Barrier, Kawau and Ponui Islands in the Hauraki Gulf, Moturua Island in the Bay of Islands and on Kapiti Island.

The largest population of brown kiwi in the South Island is in Fiordland, between the Hollyford and Waitutu Rivers. They extend east to the shores of Lakes Manapouri, Monowai, Hauroko and Poteriteri, and the Livingstone Range east of Lake Te Anau. They are also present on Resolution, Secretary and Parrot Islands. Brown kiwis are also found at Haast and at Okarito on the West Coast, and are spread throughout Stewart Island.

Threats to kiwis

Predators such as rats, stoats and wild cats, dogs and pigs have had a major impact on the kiwi population since the arrival of Europeans. During a six week period in late 1987 a wild dog killed about 50% of the 1000 kiwis living in the Waitangi State Forest in the Bay of Islands. Kiwis have also been victims of gin traps and cyanide poison laid for possums. It is common to find kiwis in lowland areas with missing toes. In part of the Waipoua State Forest in Northland, about 15 kiwis were killed on roads over an eight month period. Land clearance by both Maori and Europeans eliminated the birds in most

coastal and lowland areas of the North Island, and this continues to be a threat to some populations. Kiwis are very territorial and pairs require areas of between 1.6 hectares and 40 hectares depending on species and locality, so that large areas are required to support self-sustaining populations. In Hawke’s Bay, for example, forest remnants as large as 500 hectares lost their kiwis within two decades of becoming isolated. Two populations in that region have declined by about 50% in the past four years. Even in areas where brown kiwis seem plentiful, such as Northland and Taranaki, recent forest clearance has probably lead to a decline in reproduction. The resulting decline in population will be seen over the next two decades if nothing is done in the near future.

Why kiwis are so vulnerable to predators

Before Europeans arrived the only predators of kiwis were large birds such as the extinct eagle. It is thought they were the main reason kiwis became nocturnal and well camouflaged. They have also evolved for some 25 million years in the presence

of wekas, the only natural predator of kiwi eggs and chicks. All species developed defences against wekas, including such elaborate ploys as placing vegetation over the entrance of breeding burrows to hide their entrances. The vulnerability of kiwis to mammalian predators is therefore not because the birds lack defences, but because the ones they have evolved are ineffective against the new predators. They evolved to foil day-active birds which hunted by sight, not nocturnal animals hunting by sound and scent. Little spotted kiwis were the main victims of the new predators -- at half the size of their fellow species, they were simply too small to defend themselves.

The breeding rate factor

All three species of kiwi have long lifespans and low reproductive rates. The average life-span is probably about 10 years, with some adults living to the age of 30 or 35. Male kiwis become sexually mature at 18 months, but females do not lay until they are three to five years old. The eggs size to body size ratio in kiwis is among the greatest of any bird in the world. It takes a female 30 days to form an egg, which then takes 70 to 80 days to hatch. North Island brown kiwis and little spotted kiwis on Kapiti Island normally lay two eggs a year, 20 to 30 days apart, and some will lay a second clutch if the first one fails. Great spotted kiwis in northwest Nelson usually lay just one egg a year, and replacement layings are rare. The rate of egg production in birds further south is not known. About 75% of kiwi eggs fail to hatch. Some are deserted for no apparent reason, some are invaded by microbes, some are chipped or cracked by the incubating male, some are infertile and a few are eaten by

predators. Wekas account for the greatest loss of eggs of little spotted kiwis on Kapiti Island. At present, most populations are managing to produce enough chicks to theoretically replace themselves with young every two to eight breeding seasons. This implies that the failure of some populations on the mainland is due to poor adult and/or

juvenile survival rather than inadequate breeding. However, the relatively slow rate of breeding makes it difficult for populations to recover when faced with other threats. Kiwis have proved to be robust animals that can be handled and transported with little apparent harm. The North Island brown kiwi breeds regularly in captivity and both great and little spotted kiwis have done so occasionally.

BNZ sponsorship good news for kiwi

Fortunately, the plight of the kiwi has been recognised before the bird reaches the brink of extinction. The Department of Conservation is now well into the first stage of its Kiwi Recovery Programme, launched in August in partnership with the Royal Forest and Bird Protection Society and the Bank of New Zealand. The Plan and the partnership were first announced by a world authority on conservation, Sir David Attenborough, at the conclusion of a superb, eye-opening television documentary on the kiwi produced by the Natural History Unit of TVNZ. "Once again New Zealand is leading the way in conservation. By forming this coalition for research and action, you can address the threats the kiwi faces and ensure it can flourish at home on the mainland," said Sir David. "The Kiwi Recovery Programme is a marvellous alliance . . . and a source of great hope, because it is New Zealanders who are the guardians of this remarkable survivor." The authors of the Kiwi Recovery Plan were Dr David Butler of the Department’s Threatened Species Unit, and Dr John McLennan of DSIR Land Resources. They prepared a five year programme of research and management aimed at the long term goal of maintaining and, where possible, enhancing the current abundance, distribution and genetic diversity of kiwi. It will be co-ordinated by the Threatened Species Trust Programme, a partnership between DoC and Forest and Bird. The Bank of New Zealand will provide substantial financial support, and will also actively promote the programme through its nationwide network of branches.

The Managing Director of the Bank, Mr Lindsay Pyne, presented the Recovery Plan to the Prime Minister, Mr Bolger, at a function attended by the Minister of Conservation, Mr Denis Marshall, and Forest and Bird’s Conservation Director, Kevin Smith. In accepting the plan, Mr Bolger said the programme would ensure a more promising future for the kiwi. "We are now taking steps to save this unique bird, our national emblem, before its position becomes critical," said Mr Bolger. A whakawatea (clearing of the path) was later held at the National Museum and Art Gallery‘(Te Whare Taonga O Aoteoroa), bringing the Maori community alongside the partners to endorse the programme. Maori people wanted to participate in the Recovery Programme because of their deep relationship with the kiwi and the natural world. According to.many Maori traditions, the kiwi is the oldest of Tanemahuta’s bird family. It was Tane, the god of the forest, who, with different wives, created much of the natural world including birds, trees, stones and humans. At significant moments in Maori life deaths, marriages or other great events — the kahukiwi (kiwi feather cloak) is drawn over the shoulders

as a privileged symbol of chieftainship and high birth. The cloaks, which are nearly always named, are great taonga (treasures) that carry the wairua (spirit) of the birds themselves. Today, however, it is only through kiwi that die naturally or through things like road accidents that the Maori people gather the prized feathers and continue the tradition of kahukiwi. The Bank of New Zealand's General Manager of Group Policy and Development, Mr Thomas Tennent, said it was | significant that a world authority of the stature of Sir David Attenborough had been so forthright in his support of the partnership. "This interest and support tells us that this recovery programme has a significance that transcends our own shores, and we once again have an opportunity to demonstrate to the world our leadership in caring for the preservation of native species," said Mr Tennent. The Minister of Conservation, Mr Marshall, said the kiwi was one of our most precious treasures — a symbol of our identity and pride. "I commend this plan to you. I hope it sparks unprecedented co-operation and sustained effort to turn the kiwi away from the edge of the cliff," said Mr Marshall. #&