The Kakapo Recovery Team has gone into overdrive, with six Department of Conservation staff, in two shifts, providing five to 10 feeds a day for the chicks.
Team leader Deidre Vercoe said not enough rimu fruit had ripened on the island for all 27 mothers to feed the 34 chicks.
Some mothers were struggling to keep up with the demands of their hungry offspring, so in order to ensure their survival, some of the chicks were being hand-reared.
"We knew it was going to be a cracker breeding season, but we didn't know exactly how many chicks there would be, or if there would be enough food," she said.
Hand-rearing meant around-the-clock care and lots of feeds. The younger chicks needed at least 10 feeds a day while the older ones were on about five feeds a day, she said.
That involved weighing each chick each morning to assess how much food it needed. They were fed a commercial parrot-rearing mix with the amounts of solids increased as the chick got older.
"It involves making up the food, which takes half an hour, then half an hour to get through feeding, so that is five solid hours of feeding a day and a lot of record-keeping."
All of the kakapo were "buddied up" so they could interact together. As social birds, they seemed to enjoy human company and interaction, she said.
At the end of June, the chicks would be transferred back to Codfish Island where they would remain in pens for six weeks so they could acclimatise again to the outside world.
Meanwhile, volunteers and Doc's kakapo rangers continued to monitor the 13 chicks on Codfish Island.
"This has been a massive and pretty intense breeding season, but everyone has been amazing. Their efforts have made this an incredible year for the recovery effort," Ms Vercoe said.
Kakapo facts
• Critically endangered.
• Is the rarest parrot species in the world.
• Only exists in New Zealand.
• On Codfish Island there are:
- 32 males.
- 44 females.
- 38 breeding females.
