Reproductive biology and conservation of the endangered kakapo (Strigops habroptilus) in New Zealand

The kakapo (Strigops habroptilus) is a large, flightless, nocturnal parrot found only in New Zealand. There are currently 34 male and 22 female kakapo alive on several islands off the coast of New Zealand; these totals will increase following a successful breeding season in 1999, Kakapo are lek breeders and are the only parrot to show lek behaviour. The male birds prepare display areas called track and bowl systems during early summer. Male kakapo then spend many nights producing low-frequency calls known as booms to attract females for mating. Breeding occurs naturally only once every two to five years, and the intensity and duration of the male booming displays and the proportion of females that lay eggs can vary greatly between years. In some years females visit the lek breeding grounds to mate then lay up to three eggs and incubate the eggs for about 30 days. After the eggs hatch the female feeds the chicks herself for three months, and the chicks continue to remain with the female for some months after fledging. Efforts to save the kakapo began more than 100 years ago, and the kakapo is now the subject of the most intensive single species conservation programme for any bird in New Zealand and perhaps the world. All kakapo have been moved from their original habitats to islands where the adults are safe from mammalian predators. Every kakapo is fitted with a radio transmitter so that it can be located using radio telemetry, and the birds are all caught and checked at approximately yearly intervals. Since 1989 the management of the kakapo has been undertaken according to a recovery plan with clear goals and significant financial support. The recovery plan was revised in 1995, and very intensive management of kakapo breeding was first implemented in 1997 when kakapo bred on Codfish Island. The conservation effort now maximises the chances that every fertile kakapo egg will lead to a successfully fledged kakapo chick. The intensive conservation work has resulted in a marked increase in the breeding success of kakapo over the last three years, and the prospects for the survival of the kakapo are now better than at any time in the last 100 years.