The 2018/19 kākāpō breeding season is the largest ever on record after 71 chicks survived to juvenile age, increasing the population to 213.
Juvenile age is when a chick turns 150 days old, after which they can be officially added to the adult population. The previous record was 32 chicks surviving to juvenile age.
"There are probably more kākāpō alive today than at any time in the last 70 years," Department of Conservation Kākāpō recovery science advisor Andrew Digby said in a statement. "Decades of work from many people has gone into achieving this."
Kākāpō Recovery Group’s Ngāi Tahu representative, Tane Davis, said the success of the season has come from a joint commitment by everyone involved.
"More kākāpō means finding more pest free habitat – this will be the next challenge, but one day being in a position to return kākāpō to their wahi kainga, places like Rakiura, is the ultimate goal."
It comes after a wave of aspergillosis – a fungal infection which can be extremely deadly to birds – swept through predator-free Whenua Hou/Codfish Island this year. Twenty-one birds were affected, but have since survived.
DOC kākāpō operations manager Deidre Vercoe said the new population milestone is a wonderful reward for everyone involved in the species' recovery.
"A huge amount of effort from many people around both New Zealand and the world has gone into achieving this remarkable result," Ms Vercoe said.
The next challenge will be looking for new homes for the growing population, Ms Vercoe said.
"The kākāpō population has grown 70 per cent in the last 5 years and we're starting to reach carrying capacity on the two main breeding islands: Anchor and Whenua Hou.
"We need to find new suitable habitats for the growing population, which is a great problem to have."