Two hundred years ago, millions of kiwi lived all through New Zealand’s forests, and the night air echoed with their calls.
Today the birds are under siege. By 1998, the population had plummeted to fewer than 100,000 birds. By 2008 that figure had fallen even further – to about 70,000.
Today, in places where kiwi are being managed, things are improving and many populations are stable or increasing. These places include Department of Conservation (DOC) kiwi sanctuaries, community-led projects (many of them sponsored by Kiwis for kiwi) and offshore island sanctuaries.
There is no room to relax, however. Many kiwi live outside managed areas and these populations are expected to decline. Even within the managed areas, uncontrolled dogs can kill many birds very quickly.
A tiny proportion of kiwi eggs produce a kiwi adult.
- About 50% of all kiwi eggs fail to even hatch – sometimes because of natural bacteria, sometimes because the adult bird is disturbed by predators.
- Of eggs that do hatch, about 90% of chicks are dead within 6 months.
- 70% of these are killed by stoats or cats, and about 20% die of natural causes or at the jaws and claws of other predators.
- Only 10% of kiwi chicks make it to six months.
- Fewer than 5% reach adulthood.
According to DOC, all kiwi species are in trouble to some degree. The Department’s threat classification for each of the 11 kiwi taxa is shown in Table 1.
Table 1: Threat classification of the 11 kiwi taxa.
|Brown kiwi (all 4 taxa)||Serious decline|
|Haast tokoeka||Nationally critical|
|Northern Fiordland tokoeka||Gradual decline|
|Southern Fiordland tokoeka||Gradual decline|
|Stewart Island tokoeka||Gradual decline|
|Great spotted kiwi||Gradual decline|
|Little spotted kiwi||Range restricted|
Little spotted kiwi are on the road recovery.
Rowi have increased their population, mainly due to Operation Nest Egg™.
The decline of both Haast tokoeka and Coromandel brown kiwi has been halted thanks to extensive predator control. For Haast tokoeka, Operation Nest Egg is helping to halt the decline.
The other three taxa of brown kiwi are still in decline. Although some actively managed populations are flourishing, most birds live in sites with little or no management, and for some of these, dogs are a serious problem, especially working dogs.
The other three taxa of tokoeka have no direct management and are assumed to be gradually declining, especially in lowland and drier areas.
Great spotted kiwi receive little active management, and although some populations in upland wet areas appear to be stable, those in lowland and drier areas are assumed to be declining gradually.
The source of the threat
It can become a downward spiral. As kiwi populations decline and become fragmented, sex ratios skew and the effective breeding population further declines. And so it goes…
There are things each of us can do to help kiwi survive and thrive. Find out what here.