Kākāpō breeding – behind the scenes

Operations Manager for kākāpō, Deidre Vercoe, reflects on the role we (the Department of Conservation) have played in growing the population of this endangered species.

Why do we need to help kākāpō breed?

Kākāpō are a taonga (sacred treasure) of Ngāi Tahu. They’re nocturnal, flightless and the heaviest parrots on the planet.

Evidence shows they were once plentiful throughout the country, and they were also an important food source for Māori, and their feathers were prized for cloaks and decoration.

However once more people began to inhabit New Zealand in the 1800s, and ground-based predators such as rats, cats and stoats were introduced, the kākāpō’s inability to fly put them at huge risk.

Because kākāpō only breed every two to four years when rimu trees are fruiting, the population quickly declined due to land clearance and predation.

Searching for kākāpō to save them from extinction

In the 1960s and 70s DOC searched for kākāpō throughout Fiordland and found 18 males, but no females. Then in the late 1970s a population was found on Rakiura/ Stewart Island which included females. Breeding was observed for the first time in living memory, offering hope for their future survival.

How did DOC keep them safe?

Over the next few decades, DOC focused on transferring as many kākāpō to safe sites as possible.

The Kākāpō Recovery Programme was formed by DOC in 1995 to protect the population which by that time was 51 precious birds (50 from Rakiura and one from Fiordland).

All kākāpō currently live in habitats that have been established for them on predator-free islands in the South Island, namely Pukenui/Anchor, Whenua Hou/Codfish and Te Kākahu-O-Tamatea/Chalky islands. Pearl Island is used as a ‘parking site’ for males that are not currently in the breeding programme, and Hauturu-O-Toi/Little Barrier is a trial site to see if they can raise chicks here without supplementary food (and in the absence of rimu).

How many kākāpō are alive today?

During the 2022 breeding season 55 chicks fledged taking the new kākāpō population total to 252, a 50-year high! This is still a very small number, considering that’s all that’s left on the planet, but going from 51 (in 1995) to 252 means we are heading in the right direction.

Keeping an eye on kākāpō in breeding seasons

Kākāpō are notoriously good at staying hidden so the recovery team keeps tabs on them by fitting them with tiny backpack-style transmitters. These are changed annually, and with 252 kākāpō now in the population, this is a significant piece of field work that takes over 4 months, with a team of six people.

Kākāpō smart transmitters log daily activity data. This data is received by a network of data loggers, and then transmitted to a computer by this network, allowing the team to interpret daily activity information. If a bird becomes ill, its activity levels drop significantly, so there is a good chance the team will learn about it remotely and can then investigate.  

The science of kākāpō mating

When rimu is set to fruit and a breeding season is predicted, supplementary feeding stations are set up several months in advance to get the birds in the best condition to breed.

Male kākāpō start ‘booming’ (calling out to females) and activity data on the transmitters shows when mating has occurred (who mated, for how long) and when females start nesting.

On the ground, the recovery team makes camp near nests and installs tech gear at the nest entrance to alert them when anything enters or leaves the nest along with a data logger placed inside the nest, to record when mum is in attendance. This allows rangers to check eggs and chicks when mum is off the nest as well as keeping an eye on how much time mum is spending off collecting food.

Incubation and hand-rearing rooms are made ready, and a team of fit and skilled people cart gear around, interpret data, and put management plans into action.

Improving tools to help kākāpō to flourish

As well as having built all the nest technology and developed the remote monitoring systems used, the electronics workshop team at DOC is leading the design of a new transmitter, which will last for at least two years and have a new quick-change harness design. This will reduce the time handling the birds and will improve the range for better remote monitoring.

Understanding how genetics can improve health and breeding success is another area of research. Nine chicks were successfully fathered using Artificial Insemination in 2022, proving that Artificial Insemination is a viable tool to support recovery. Having the full genomes sequenced for all living kākāpō (through the kākāpō125 programme) is leading to increased externally-led research and for more individual-based management of the population.

And to power all of this work, specialised infrastructure/hut and power-systems are needed.  Kākāpō Recovery’s National Partner Meridian Energy has played a significant role in upgrading the huts’ solar power systems, making them far more reliable and greatly reducing the reliance on generators on the remote island sites. Meridian continues to contribute their support, aiding the recovery tea m in their innovative solutions.

What’s next for kākāpō?

As kākāpō numbers grow, finding new predator free sites is crucial. Planning is underway to establish new habitats as possible, but suitable habitat availability is now our biggest challenge. Watch this space! The recovery programme currently has a reasonably intensive and individual-bird-focused approach, but as the population increases with each breeding season, we are taking steps to reduce this intensity and focus more on the population level.  The population has doubled since 2016 – so we’re in an exciting transitional phase for kākāpō.  What will the next chapter of their recovery look like?

Together with Ngāi Tahu, Predator Free Rakiura, Meridian, volunteers, community groups, and New Zealanders trapping pests in their backyards, DOC keeps striving to carve a pathway to restore the mauri (lifeforce) of kākāpō in its homeland.