The four baby kākāpō were among 26 chicks removed from the island in April and hand-reared in a special facility in Invercargill after a shortage of their staple diet - ripened rimu fruit - threatened the chicks’ survival.

Now 90 days old, the chicks will spend up to six weeks in temporary outdoor pens while they acclimatise to the island conditions and are weaned off the hand-rearing food.

At the end of their acclimatisation, each kākāpō will be fitted with a tracking transmitter and slowly introduced into the wild in small groups around the island.