Operation Nest Egg

Our breeding programme is run with the ongoing and invaluable support of Willowbank Wildlife Reserve
Kiwi in New Zealand are undergoing a serious decline in numbers, mostly due to the effects of predators. Currently in the wild, 88% of kiwi chicks hatched in the North Island are killed within one hundred days of hatching. The most destructive predator of kiwi are stoats. It is estimated that they alone account for the deaths of 40% of the 88% mentioned above. It is estimated that the mortality rates are up to 95% for South Island species. These are alarming statistics for the continued survival of the bird which is our national icon. 
With the help of modern technology and a specially trained 'kiwi' dog, breeding pairs of kiwi are located in the wild. A  transmitter is attached to the male's leg as generally he sits on the egg more than the female. The male is left to sit on the egg for about 30 days. During this period the male looks after the processes of turning the egg and allowing for cooling periods when he is off the egg to feed. 
After 30 days, the egg is lifted from the burrow and brought to the Trust facility in Christchurch. The egg is cleaned, removing any potentially harmful bacteria, and is placed in a carefully prepared incubator.
At this stage the egg is monitored as are temperature and humidity levels in the incubator. The egg is weighed and this detail, along with the condition of the egg and the date it was lifted from the nest, is recorded. The egg is weighed daily and these weights are also recorded. This process allows for tracking of the weight loss which is expected during the incubation of an egg. An egg is expected to lose between 12 – 16% of its weight during the incubation time. Regular timed cooling off periods are provided to emulate the processes of the male in the wild.
Candling involves shining a special light through the air pocket at the end of the egg and this allows keepers to check on the chick inside the egg. During candling, which is done sparingly due to the light, the keeper is checking air-cell enlargement, embryo development and the clarity and condition of the inner membrane and network of veins, all of which are good indicators of the health of the embryo. The regular turning of the egg in the incubator mimics the actions of the male in the wild. It prevents the chick inside sticking to the internal egg membrane, and allows the embryo to absorb nutrient from the egg albumen. This process of turning is done with a great deal of care to ensure the egg is never completely inverted. The egg is only turned in intervals of 45 degrees each time and follows a set pattern of turns.
After a period of time in the incubator the chick hatches; total incubation period is approximately 80 days. The first stage of hatching for the kiwi chick is known as the ‘internal pip’ and involves the chick breaking through the membrane between itself and the air-cell at the top of the egg. The next stage is the ‘external pip’ and this process can take up to 100 hours and often noises from the chick inside the egg can be heard during this time. The 'external pip' involves the chick cracking the shell with its beak and enlarging this hole, also with the beak. The feet are used to help kick the shell free from its body. The process of 'external pipping' can be a slow and delicate procedure.
At this stage of hatching, intervention is occasionally necessary if the chick is having difficulties. This is generally given after the 100 hour period. Any intervention at this stage is very carefully and gently undertaken by experienced staff, as this is a critical stage for the baby chick.
After hatching the new chick is weighed and this information recorded. The new kiwi will also have its umbilical cord disinfected.
The next step for the kiwi chick is to be placed into a special unit known as the TLC (thermal life support cabinet). This is where the chick will spend the next two/three days under close supervision and care from keepers. The TLC unit helps the chick to dry out and provides a closely monitored and balanced environment. During this time the chick is sustained by the yolk sac which is contained within the bird. This yolk sac nourishes the chick for up to two weeks. It is normal for the bird to lose weight during the first two weeks where after it can potentially take a further two weeks to reach its hatching weight.
After three days the chick is big enough to be moved into a brooder pen. This pen has a deep floor covering of peat, a burrow and the other necessities such as water, worms and small stones for the birds gizzard. For the first week an incubator lid, which has a special element in it, is placed inside the burrow to keep the chick at the right temperature. As the chick grows older the temperature in this incubator lid is gradually lowered until it is in line with the room temperature. An ambient room temperature of 20 degrees is ideal at this stage. In this brooder pen the chick will start to receive a specially formulated diet which is weighed, allowing us to track how much food the kiwi is eating. The bird is weighed daily for two months, then less regularly after this.
Once the chick has reached an appropriate weight of 450 grams, it is taken to either a predator-free island or inland creche site. However, there is often a situation which requires the kiwi chick to remain for a longer period. The chick is then placed in a special area known as a pre-release pen. These larger pens have a burrow for the bird as well as an area to allow for natural feeding habits such as probing to take place. During this time the amount of food the kiwi eats is recorded daily and the bird’s weight is checked on a weekly basis. These pre-release pens are a ‘hardening off’ area before potential release into the wild.
Once the chicks are released into predator-free creche sites/ islands they will be monitored to ensure they are putting on sufficient weight. Should their weight drop, then supplement food is supplied until the chick adjusts to looking for food by itself.
The chicks will remain in these protected creche sites until they reach 1.2 kgs. At this weight they can protect themselves from a number of predators.
Before the young adults are released back into the wild they have  transmitters placed on one of  their legs and a micro chip inserted under a wing.
These young birds will continue to be monitored in the hope that one day they too will be adding to the kiwi population.

A great way to help protect kiwi and other native species is to become involved in trapping programmes. Find out more about the New Zealand Conservation Trust's predator control programmes. 
        Kiwi dog and handler
        egg retrieval

        Recording information about the egg
SH and FC working 021-701

       Chick hatching

       New kiwi chick

       Chick in TLC unit

       GSK chick in brooder pen

       Measuring bill length

       Chick released into predator free creche site

60 Hussey Road
New Zealand

+64 3 359 6226 ext 704

Charities Registration Number: 21020