Kākāpō population cracks record high after booming breeding season

After a bumper breeding season, the kākāpō has officially reached a record high at 213 birds.

It's thrilling news for conservationists who have battled to preserve the endangered native species. 

"I think we owe it to the world to try and save these pretty amazing bird species," Dr Andrew Digby, Department of Conservation's (DoC) Kākāpō Recovery science advisor, told Newshub.

"They're one of the rarest birds in the world... They very nearly became extinct."

It's taken decades of work to get to this level; in the mid-90s, there were only 51 adults kākāpō.

"There are probably more kākāpō alive today than at any time in the last 70 years."

The official population isn't updated until chicks are deemed "juvenile" at 150 days old, Dr Digby said. This is because chicks often struggle to thrive.

Stella-3-B-2019 is the youngest chick from the latest breeding season and hit the milestone on Tuesday.

"Breeding seasons like the ones we've just had, they're the ones that really make the gains and increases in population," Dr Digby said.

"We want to get more kākāpō. We'll start to be a bit happy once we've got to around 500 birds and we've got some in a self-sustaining population."

Kākāpō chick Stella-3-B-2019.
Stella-3-B-2019 is the youngest chick from the latest breeding season. Photo credit: Dr Andrew Digby / Department of Conservation

As well as hitting a record high population, this breeding season soars above the previous record for number of surviving chicks.

The latest record was 32 chicks surviving to juvenile age. It was more than double this year, with 71 survivors.

However, reaching juvenile age isn't a guarantee of future survival. Fungal disease aspergillosis swept through Whenua Hou/Codfish Island this year, killing a number of birds while others are still recovering.

"That hit us really hard... There's been a huge amount of work going on to diagnose and treat those birds affected," Dr Digby said.

"The population will decrease before it increases again. Not all of these juveniles will survive to adulthood, and we'll likely lose some adults too.

"Despite the population increase, kākāpō are still critically endangered."

A major mast year meant more food (rimu fruit) for the breeding kākāpō, but it's a double-edged sword - it's also more food for predators like rats, which also saw a population spike. 

There are three dedicated predator-free islands housing kākāpō, but room is expected to run out eventually.

"More kākāpō means finding more pest-free habitat - this will be the next challenge," Kākāpō  Recovery's Tane Davis said in a statement.

"But one day being in a position to return kākāpō to their wahi kainga (homeland), places like Rakiura, is the ultimate goal."

Why it's so hard for kākāpō to breed


In 1995, there were just 51 kākāpō alive. Before this breeding season, there were 148.

kākāpō don't breed very often and have a high infertility rate, DoC's threatened species ambassador Nicola Toki told The Project.

Dedicated staff work around the clock to monitor eggs, help them hatch, and help raise the baby chicks before returning them to their parents.

Of the 252 eggs laid this breeding season, only 118 were fertile. And of that, only 86 successfully hatched.

"There's a massive potential there, really increasing the kākāpō population by a huge amount, but we've ended up with only 71 chicks so far," Dr Digby said.

"I say 'only' because that's still a massive number when we had 147 adults at the start of the year.

"We could have had over 100 more kākāpō produced if we didn't have those fertility problems."

It means every chick is treasured - each baby a new life to restore the species to its former glory.