Science / Environment

Bonus Episode: 2022 A Boomer Year for Kākāpō

05:00 am on 28 April 2022

It’s been very quiet on the kākāpō front for the last two years, but this year is another big one for the rare bird.

Kākāpō recovery programme manager Deirdre Vercoe and range Scott Latimer carry out a health check on a chick. Photo: Alison Ballance

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In 2019, the endangered flightless night parrot had its largest breeding season on record, as recounted in the RNZ podcast series the Kākāpō Files and Voice of the Kākāpō. After a rollercoaster ride of successes and setbacks, 72 chicks fledged, temporarily boosting the kākāpō population to 213 birds.

Since then, there has been a slow attrition due to deaths of both old and young birds, which saw this breeding season kick off with 201 birds.

Most importantly, this number included 57 females of breeding age, which are spread across three southern kākāpō islands: Pukenui-Anchor Island (in Fiordland), Te Kakahu-Chalky Island (also in Fiordland) and Whenua Hou-Codfish Island (near Stewart Island). Forty six of those females have bred this year, laying a grand total of 139 eggs.

The forest on Pukenui Anchor Island contains many podocarp tree species such as rimu which are important triggers for kākāpō breeding. Photo: Alison Ballance

By autumn, 57 chicks out of the 60 that hatched were doing well, most of them being raised by their mothers or foster mothers. In previous breeding seasons many chicks have been hand-reared, but Deidre Vercoe, manager of DOC’s Kākāpō Recovery Programme, says that this year the team was taking a more hands-off approach. This meant no double clutching, and most eggs were left to hatch in nests rather than in incubators.

There is now a much greater reliance on technology to allow remote monitoring, with every bird wearing a smart radio transmitter that sends information about the wearer to a centralised computer database. Te Kakahu-Chalky island is the most hands-off breeding island, and indications from activity records being sent remotely from the three nesting mothers suggests they are still raising the island’s three chicks.

Rium fruit carpet the forest floor and provide a plentiful food supply for growing kākāpō chicks Photo: Alison Ballance

Aspergillosis outbreak

Female kākāpō Boomer in a travel crate returning from a health check Photo: Alison Ballance

Unfortunately, the onset of autumn marked a bit of a turning point in the breeding season. After a period of hot dry weather in Fiordland, the female Jemma, on Pukenui Island, died from aspergillosis. This fungal disease can be deadly, with nine kākāpō dying from it in the 2019 breeding season, although a number of other kākāpō were successfully treated.

A second Pukenui female, Roha, has since been diagnosed with severe aspergillosis and is fighting for her life at Auckland Zoo. Some chicks are at the Dunedin Wildlife Hospital being treated for aspergillosis as well as injuries such as broken legs.

The kākāpō team has sent one adult and a dozen chicks from Pukenui to Dunedin to be CT scanned as a precaution. All bar one are clear of the disease and have been returned to their mums, and the team is keeping a close watch in case other birds develop symptoms.

Deidre Vercoe transfers a kākāpō chick into a travel crate ready to be sent to the Dunedin Wildlife Hospital for a CT scan Photo: Alison Ballance

The abundant rimu crop is ripening well and most chicks this season weigh well above average. The oldest chicks are already fledging and leaving the nest, although still being fed by their mothers.

It’ll be a few months before the youngest chicks reach the milestone of 150 days and get counted as sub-adults, and a lot could happen between now and then. But barring disaster, the kakapo population will top 250 birds this year – the bird has come a long way since the mid-1990s when there were just 51 individual kākāpō alive.

This year’s baby boom means the Kākāpō Recovery Programme is looking very hard for new locations to move birds, as the current predator-free islands are full. There is talk of erecting a predator-proof fence around a large area of forest near Wainuiomata, in the Hutt Valley, and if that proposal succeeds the idea is to relocate some kākāpō there.

Want to know more

  • Check out Voice of the Kākāpō, an audio adventure through the 2019 breeding season, as told by Deidre Vercoe, Andrew Digby and Daryl Eason from the Kākāpō Recovery Programme.
  • In the Kākāpō Files, Alison Ballance followed along with the 2019 breeding season as it unfolded.
  • Jesse Mulligan caught up with Andrew Digby for an update in late March 2022.
  • To keep up to date with all the kākāpō news, follow Andrew Digby on Twitter or the Kākāpō Recovery Programme on Facebook.