Great spotted kiwi/roroa (Apteryx haastii) are rugged mountaineers with soft, mottled grey-brown plumage.
The great spotted kiwi is the tallest kiwi species, at about 45 centimetres tall.
Today, they are found in three discrete natural populations – northwest Nelson, the Paparoa Range, and near Arthur’s Pass. Birds have also been transferred to Lake Rotoiti mainland island, in Nelson Lakes National Park.
It is thought great spotted kiwi have been in part protected by the high altitudes they live in. The harsh conditions make it tough going for the dogs, cats, ferrets and stoats that would otherwise prey on them.
All population numbers quoted are based on 2015 estimates unless otherwise stated.
Less is known about great spotted kiwi populations than the other kiwi species. Because the birds are still numerous, research effort has instead been concentrated on species that are in serious trouble – such as rowi and Haast tokoeka.
However, long-term intensive monitoring shows that populations of great spotted kiwi have remained remarkably stable over 20 years.
One reason their populations appear to be stable, especially those in wet upland areas, is because most great spotted kiwi live in national parks, where dogs are banned and there are large areas of protected native forest. By comparison, in Northland, dogs are the biggest threat to brown kiwi.
Another possible reason is that the places great spotted kiwi live are very inhospitable to their predators. That is, the birds live in beech forest, which is unlike most North Island kiwi habitat. When beech trees flower (mast), the number of predators, including stoats, rapidly increases and many kiwi chicks may be killed. However, most years are non-mast years, and there are much fewer predators around. That means it is likely that most chicks survive, regularly pulsing new birds into the population and keeping it stable over time. In North Island forests, predator numbers tend to be high all the time, unless some management action is taken to trap or poison them.
Some birds are killed by cars on roads in Arthur’s Pass and in the Buller gorge, and one was killed by a train, but these deaths are relatively small in number.
For these reasons, researchers say it is not valid to assume the issues facing North Island brown kiwi are having the same impact on great spotted kiwi.
Nonetheless, it is assumed that populations in lowland and drier areas are slowly reducing, which means that overall, great spotted kiwi are classified by the Department of Conservation (DOC) as in ‘threatened (nationally vulnerable)’.
While great spotted kiwi have received little active management in the past, apart from aerial 1080 operations, this is changing. Community-led initiatives are now under way in Nelson, the Paparoa Range and Arthur’s Pass, and the first Operation Nest Egg™ chicks were produced during 2007/08. Of the estimated population of 14,800 birds, 12.6% are under active management. Despite this, the taxa is predicted to decline by 1.6% over the next 15 years.
The table below shows the estimated great spotted kiwi population in 2008 and 2015, and what it could be in 15 years time.
|Region||Estimated 2008 population||Estimated 2015
|Northwest Nelson to Buller River, Paparoa Range, Southern Alps (Arthur’s Pass to Lake Sumner)||16,000||14,800||12,428|
As with other kiwi species, great spotted kiwi pairs have only one mate at a time. The birds also generally mate for life, though divorces do sometimes happen.
Eggs and clutches
Great spotted kiwi typically have just one egg in a clutch, but can occassionally have two clutches in one season.
Incubation is shared more-or-less 50:50 between the parents. Males do a little more as they incubate during the day and share the night roster with the female. This allows both birds to feed. Both parents are often in the nest at the same time.
Great spotted kiwi do not feed their chick. Young birds stay in their parents’ territory for a year or more, either with or nearby the adults. This is different to little spotted kiwi, where the chicks are completely independent at less than two months of age.
Operation Nest Egg
Great spotted kiwi were brought into Operation Nest Egg in the 2007/08 season. Several small-scale Operation Nest Egg projects are now under way, with eggs and chicks sourced from northwest Nelson, the Hawdon Valley (Canterbury) and the Paparoa Range populations:
- Northwest Nelson birds are released into the Rotoiti mainland island, to build up the genetic diversity of that population.
- Of the birds sourced from the Hawdon Valley, some were placed in the Nina Valley, near Lewis Pass, to establish a new great spotted kiwi population.
- Paparoa birds are released back into their source site, after a stay in the specially built kiwi crèche.
In most cases, eggs are taken from great spotted kiwi burrows. However, because burrows are often deep, sometimes eggs cannot be easily reached and newly hatched chicks are taken instead. DOC prefers to take eggs as this can prompt the parents to re-nest and lay further eggs, which boosts the population more quickly.
No formal kohanga kiwi populations exist for great spotted kiwi.
Great spotted kiwi live in forested mountains from sea level to 1500 metres, but mainly in the subalpine zone of 700-1100 metres. They use a wide variety of habitats, including tussock grasslands, beech forests, podocarp/hardwood forests and scrub.