If kākāpō do breed, we occasionally 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.
Forty-nine kākāpō have been hand-raised and returned to the wild and now comprise 39% of the total kākāpō population. Most, if not all would have died early in life without rescue. Some have remained tame toward humans, but many 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 4-5 months old and raised in the company of other kākāpō chicks, to avoid negative imprinting toward humans and improve their chances of breeding.
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 came close to achieving this aim in the 2009 season – seven chicks were raised in the nest only because their mothers fed them the supplementary food. We do not yet know why just a handful of the mothers passed this food on, when most had access to it.
Perhaps it is a learned behaviour, or perhaps the diet is not quite right yet.