If kākāpō do breed, we regularly need to remove either the eggs or chicks from the nest and care for them ourselves.
This might be because the mother has too many eggs to raise herself or because a chick is sick or underweight.
Raising the chicks is not so difficult now that we have learnt about their food, temperature, humidity and social requirements. Initially we began with little information and encountered obstacles along the way, which was exacerbated by dealing with only a few eggs or chicks at a time.
Sixty-nine kākāpō have been hand-raised and returned to the wild with a survival of 91%. These hand-reared birds now comprise 41% of the total kākāpō population. Most, if not all would have died early in life without rescue. Some have remained tame toward humans, but most are now indistinguishable from wild birds.
On one occasion, we cared for a chick in captivity right up to the age of five. Hoki became so famous and well-loved that a book was written about her by her keeper. She raised her first chick when she was 10, in 2002.
Hand-raised kākāpō are now returned to the wild when 4 months old and raised in the company of other kākāpō chicks, to avoid negative imprinting toward humans and improve their chances of breeding. In 2016 we were thrilled that 16 hand-reared female kākāpō nested and ten successfully fledged healthy chicks. These ten were all first time mothers.
In the 2009 season, 26 out of 33 chicks needed to be hand-raised when the rimu crop failed. Getting such a large number of chicks through to fledging was a huge effort for all those involved. One of the main aims of our Supplementary Feeding Trials is to produce a pellet diet that the mothers will feed to their young when the fruit crop fails.
Kākāpō Recovery have raised more chicks in nests as a result of supplementary feeding and nest management since the 2009 season. This involves giving a fertile egg or chick from another nest to mothers with infertile eggs; or swapping slow-growing or ill chicks from nests with a healthy hand-reared chick of similar age. Sometimes we provide hand-feeding to chicks in the nest within the first four days of hatching, if their mother is a little slow to start feeding. In 2016, 23 mothers raised 24 chicks on both Anchor and Whenua Hou/Codfish Islands. Twenty females nested on each of the two islands in 2016, but the chicks raised in nine nests on Whenua Hou/Codfish Island were raised in the nest only because their mothers fed them the supplementary food. Whereas the mothers on Anchor Island used very little supplementary food, because there was an abundant crop of ripe rimu fruit available for chick feeding.
Perhaps it is a learned behaviour, or perhaps the diet is not quite right yet.