Today New Zealand’s national icon is under siege. By 1998, the population had plummeted to less than 100,000 birds.  By 2007 that figure has fallen even further – to about 78,000.

On the two main islands, the numbers and distribution of kiwi is in rapid decline.  Without island and mainland sanctuaries, and Bank of New Zealand Kiwi Recovery, the kiwi’s future would be much less promising. 

Kiwi face threats from three main directions – predators, people and losing habitat.

It can become a vicious downward spiral.  As kiwi populations decline and become fragmented, sex ratios skew and the effective breeding population further declines.   And so it goes.   

Every one of the kiwi species and varieties (individually known as ‘taxa’) are officially classed as threatened by the Department of Conservation.  Some are worse off than others.

The Department of Conservation’s Threat Categories

The Department of Conservation classification system has seven categories for threatened species. They are:

Level	Category	Level of Risk
1	Nationally Critical	Very small population or a very high predicted decline - Acutely threatened
2	Nationally Endangered	Small population and moderate to high recent or predicted decline
3	Nationally Vulnerable	Small to moderate population and moderate recent or predicted decline - Acutely threatened
4	Serious Decline	Moderate to large population and moderate to large predicted decline OR - Chronically threatened
5	Gradual Decline	Moderate to large population and small to moderate decline - Chronically threatened
6	Sparse	Taxa that are rare but not known to be declining, with small, widely scattered populations - At risk
7	Range Restricted	Restricted to small geographic area, a particular habitat, or a very specific substrate, with 10 sub-populations At risk

The six kiwi taxa fall into four of the seven categories.

Nationally Critical

The Rowi  and Haast Tokoeka  are at the top of the threatened list.  Both are classified as ‘nationally critical’ because they have such small populations, and these are in decline – about 250 Rowi are left, and only about 300 Haast Tokoeka. 

Serious Decline

While the total numbers of Brown Kiwi may seem a lot (25,000 birds), the bird is classified as in ‘serious decline’ because its populations are projected to decline by more than 50 per cent over three generations.  That is, the overall population is declining at 4 - 5 per cent each year.  This means the population halves about every 15 years.

Some populations are declining faster or slower than the average.  Faster declines are mainly due to the presence of dogs and ferrets which prey on adult birds, the ones that breed.  Stoats and cats take a heavy toll on young kiwi during their first three months.

Nationally Vulnerable
Southern Fiordland Tokoeka, with an estimated population of 5000, are classified as ‘nationally vulnerable’ as they have a small population and a moderate predicted decline.
  

Gradual Decline

Two kiwi taxa are classified as being in ‘gradual decline’ (the Northern Fiordland Tokoeka and Great Spotted Kiwi) because it is suspected that their South Island populations have a historic decline of about 2 per cent each year.  Without management, these populations are expected to halve every 35 years.  The exception may be Great Spotted Kiwi populations in high altitude wet sites, such as the Gouland Downs (Kahurangi National Park), which appear to be stable.

There is potential for rapid decline on Stewart Island if mustelids (such as stoats and ferrets) become established there.  This population seems to be stable at present.

Range Restricted

Little Spotted Kiwi, which nearly all live on Kapiti Island, are classified as 'range restricted' because their entire population of about 1,500 birds occupies less than 100 square kilometres (10,000 hectares).  The Little Spotted Kiwi population is currently increasing.

The Stewart Island Tokoeka are also classified as ‘range restricted’.  The population is considered stable at about 20,000, as long as stoats and ferrets don’t get to the island.