Kiwi eggs and chicks are removed from the wild and hatched and/or raised in captivity until big enough to fend for themselves – usually when they weigh around 1200 grams. They are then returned to the wild.
An Operation Nest Egg™ bird has a 65% chance of surviving to adulthood – compared to just 5% for wild-hatched and raised chicks.
The tool is used on all kiwi species except little spotted kiwi.
You can view footage of a chick hatching on our YouTube channel.
The idea for this tool was hatched in 1994 when researchers noticed that almost all kiwi chicks were killed by stoats, but adult kiwi were not.
With funding from BNZ, a pilot was run that adapted techniques ‘operation nest egg’ technique specifically to kiwi.
The skills for collecting, transporting and incubating kiwi eggs, then keeping young chicks alive in captivity, were honed on brown kiwi. With only 5% of wild-hatched chicks surviving to adulthood, there was nothing much to lose.
It worked - Operation Nest Egg has been incredibly good for quickly growing kiwi populations near the bring of extinction, such as the critically endangered rowi and Haast tokoeka. It has also been very effective in helping establish newpopulations.
Since 1995, the tool has been used every breeding season, largely in the most vulnerable kiwi populations, buying researchers the time to find solutions to the problems facing kiwi. The aim is to develop long-term cost-effective and sustainable ways to keep large areas of forest free of predators.
Operation Nest Egg's use decreases as each kiwi population grows, and kiwi researchers expect there may come a time when it will no longer be needed as a management tool, although its power as an advocacy tool - giving people an opportunity to get close to kiwi - will remain immensely valuable.
You can find out how it works here.
Operation Nest Egg™ owes its success to the commitment of hundreds of people. The combined efforts of DOC staff, volunteer community groups, iwi, researchers and the staff of captive rearing facilities raise more than 200 chicks each year.
Captive-rearing facilities in the North and South Islands support Operation Nest Egg, in partnership with the Department of Conservation. These include: Auckland Zoo, Kiwi Encounter at Rainbow Springs in Rotorua, the Whangarei Native Bird Rescue Centre, Napier's Westshore Wildlife Reserve, Otorohanga Kiwi House, Willowbank Wildlife reserve in Christchurch and the West Coast Wildlife Centre in Franz Josef.
Most chicks are hatched at Kiwi Encounter (more than 120 eggs a year) and Auckland Zoo (up to 20 eggs each year). Willowbank Wildlife Reserve and the West Coast Wildlife Centre focus mainly on New Zealand’s two most endangered kiwi – Okarito’s rowi and the Haast tokoeka.
Kiwi crèches are the second vital part of Operation Nest Egg. Hatched and healthy young birds are sent to these predator-proof sanctuaries until big enough to safely return to the wild. Many crèches are managed by community-led kiwi groups, with support from their communities and BNZ Save the Kiwi Trust.
Alongside these efforts, Operation Nest Egg would not succeed without the ongoing generous financial support of New Zealanders.
A conservation success story
There are four main reasons that BNZ Operation Nest Egg™ is such a powerful kiwi conservation tool
It has passed many milestones since 1995.
Most kiwi are strictly night-time birds. The main reason is food – when the sun goes down, underground insects move up closer to the soil’s surface. Southern tokoeka, on Stewart Island/Rakiura, are the exception.