The kākāpō is one of the world's rarest birds, and in the first episode of the Kākāpō Files we learn about the giant flightless parrot's 'love triangle.'

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In episode 2 of the Kākāpō Files we find out that when it comes to kākāpō breeding the early birds are, well, very early.

It's the summer solstice, and things are definitely hotting up in the kākāpō world.

DOC's Kākāpō Recovery Programme scientist Andrew Digby says there is lots of booming action amongst the male kākāpō on Whenua Hou/Codfish Island.

And manager Deidre Vercoe has some breaking news about a pair of early birds, Pearl and Boss.

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Kākāpō breeding action really kicked off on Christmas Eve and in episode 3 of the Kākāpō Files we discover it is in full swing.

Let's not be coy about this. Lots of kākāpō are having lots of kākāpō sex.

And the first eggs of the 2019 kākāpō breeding season have been laid.

DOC's Kākāpō Recovery Programme manager Deidre Vercoe couldn't be happier. She says the kākāpō breeding season on Fiordland's Anchor Island got fully underway on Christmas Eve, and is in full swing.

More than half of the 21 young kākāpō female on Anchor Island have already mated, and island rangers confirmed on the 2nd of January that the first eggs have been laid in two nests, belonging to Waa and Waikawa.

Deidre says she is particularly pleased that Kuia, a female with important Fiordland genes, has mated with several different males. Mating with multiple males significantly increases the chances that eggs will be fertile.

Meanwhile, down on Whenua Hou/Codfish Island, the female Pearl is incubating three eggs, and other birds have started mating.

Kākāpō scientist Andrew Digby says that it is too early to know if Pearl's eggs are fertile, but island rangers will be checking their fertility in a day or two.

Andrew says it is good news that Nora, one of the founder birds from Stewart Island, has mated. She successfully bred for the first time in more than 30 years during the 2016 breeding season.

Unfortunately the death of Piripi, another founder bird, lowers the total kākāpō population to 147.

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Don't count your kākāpō chicks until they hatch, kākāpō leaky homes and lots more kākāpō sex, all in episode 4 of the Kākāpō Files.

The 2019 kākāpō breeding season continues at breakneck speed.

Nineteen of 21 females on Anchor Island have mated and are starting to nest.

Down on Whenua Hou/Codfish Island, the action is also hotting up - but there is some disappointing news from Pearl's nest.

In episode four of the Kākāpō Files, we find out the truth behind the old saying 'don't count your eggs until they hatch', and we hear about leaky homes when it comes to kākāpō nests.

Kākāpō ranger Brodie Philp and kākāpō technical advisor Daryl Eason have just returned from Anchor Island and we catch up with them for all the latest news.

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The most popular kākāpō males will get a chance to do it all over again as the females are encouraged to mate and nest for a second time, in episode 5 of the Kākāpō Files.

How are the male kākāpō measuring up in the popularity stakes with the females? Young male Tākitimu is super-stud of the year... so far.

And the Kākāpō Recovery Team from the Department of Conservation are going to try a radical approach to making as many kākāpō babies as possible - they'll hand-rear the first batch of chicks and hope the females nest again.

Being courageous and inventive has helped the Kākāpō Recovery Team increase the kākāpō population from 51 birds to 147 birds in just over 20 years, and they are out to make the most of this bumper breeding season.

Manager Deidre Vercoe says they plan to get every female to renest. She says they do this by removing eggs from the nest, which usually prompts the female to mate and lay again.

Deidre says they can do this because it is such an early breeding season, and the hope is that it will boost the number of chicks produced.

Renesting was tried with 12 females in the 2016 breeding season and eight females successfully nested a second time.

To date, 19 out of 21 females on Anchor Island have nested, and the island rangers have found 16 nests. Unfortunately around half of all kākāpō eggs are infertile, and that is the case so far, out of more than 30 eggs already laid.

The breeding season on Whenua Hou/Codfish Island is several weeks behind Anchor Island. Twenty one out of 29 females have mated, and the island rangers have found 4 nests so far.

Deidre says that the first female to nest, Pearl, has already mated again, after her nest was abandoned following an altercation with a petrel.

Kakapo scientist Andrew Digby says that while all the male kākāpō are booming well, only a few of them will successfully attract a female to mate with. But a small number of birds - the super-studs -will be very successful.

So far this breeding season, success seems to be running in the family. Sixteen-year-old Tākitimu, on Anchor Island, is the most successful male to date, having mated 11 times with six different females.

His father Basil is also high in the popularity stakes: six matings with three different females.

Meet Pearl and Boss

Pearl hatched in 2002. Her mum is Alice and dad is Waynebo. She started breeding when she was nearly 7 years old. Her first two chicks from the 2009 breeding season were Jemma and Juanma. They have a place in kākāpō history as they were fathered through artificial insemination.

Pearl is a good mother. In 2016 she produced three more chicks - Attenborough, Punga and Faulkner…

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Forty eight out of fifty kākāpō females on the southern islands have mated, nesting is well underway and the first AI has been carried out, all in episode 6 of the Kākāpō Files.

It's nearly a full sweep on the southern kākāpō islands, with 48 out of 50 females having mated - a record number.

All of the females on Anchor Island have nested, and on both Anchor and Whenua Hou the Kākāpō Recovery Team is bringing in eggs for hand rearing, in the hope that females will mate again.

The Sperm Team has also begun work, collecting sperm from genetically desirable males to allow artificial insemination of some equally important females, giving the species a genetic helping hand.

The kākāpō team is rushed off its feet, keeping up with the busy birds.

It's a full house on Anchor Island, where all 21 females have mated - and nested. The egg tally there is a mighty 75, but so far only 19 of the eggs that have been checked have been found to be fertile. Some eggs are too young to determine whether they are fertile yet.

The island rangers on Anchor Island are working to bring all the fertile eggs to the hut to be incubated, freeing females up for a second nesting attempt.

On Whenua Hou/Codfish Island, 27 out of 29 females have mated so far. Hoki - the first kākāpō to be hand-reared, back in 1992 - has not mated yet, and neither has Mahli. Mahli is almost 5 years old, and very young, but her sister Tohu has just mated.

The Whenua Hou rangers have so far brought 10 fertile eggs down to the hut, to be artificially incubated in the nursery Portacom next to the hut.

Senior technical officer Daryl Eason and the Sperm Team have begun collecting sperm from males with desirable genetic traits. The sperm is used to artificially inseminate females, a job which can be undertaken about 3-7 days after a female has mated.

Daryl says AI has several aims: the more times a female mates, the greater the likelihood that her eggs will be fertile. It is also an opportunity to pass on genes from the founder males which either haven't bred at all or have only produced a small number of chicks.

So far, Daryl says they have collected a good sperm sample from Luke, a Stewart Island bird with no offspring. It has been used to artificially inseminate Jean, a Stewart Island female with only three offspring.

Daryl reports that Gulliver, one of two males with desirable Fiordland genes, has just mated with two females on the same night, including Tohu.

Update 28 January 2019

Hoki has mated, bringing the number of females who have mated to 49 out of 50.

So far, 119 eggs have been laid. Of these, 36 are fertile, 64 are infertile and 19 have yet to have their fertility confirmed.

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The first two chicks of the 2019 kākāpō breeding season have hatched and the exciting news keeps coming in, in episode 7 of the Kākāpō Files.

The first chicks of the 2019 kākāpō breeding season have hatched.

The first kākāpō chick hatched at 8.30pm on the 30th January 2019. Its mother is Waikawa, and its father is probably Horton. It was conceived on Anchor Island and hatched in the incubator room on Whenua Hou/Codfish Island.

The second chick hatched mid-afternoon on the 31st January. Its mother is Tiwhiri.

By the end of January, 49 out of 50 kākāpō females on Anchor Island and Whenua Hou/Codfish Island had mated. Hoki, the first kākāpō to be hand-reared, is the latest female to mate, and only young Mahli, who is not quite 5-years-old, has not mated.

All but 7 females have nested so far, and between them they have laid 136 eggs. This number will increase as more females nest and lay.

Kākāpō scientist Andrew Digby reports that only 43 percent of the eggs have been fertile, which is less than usual.

Infertility is thought to be due to high levels of inbreeding in the population. The Kākāpō Recovery Team is carrying out an assisted breeding programme to maximise genetic diversity, and Andrew reports that they have carried out artificial insemination on three females so far.

Breaking news

1 February update: breeding has begun on Hauturu/Little Barrier Island in the Hauraki Gulf. Lisa has mated with Jester.

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The chicks that have hatched are off to Dunedin, the females have started mating again, and there is breeding action on Hauturu, all in episode 8 of the Kākāpō Files.

The Kākāpō Recovery team continue to be very busy. Seven... oh no, make that eight already... kākāpō chicks have hatched (and counting) and the first batch are heading to the Dunedin Wildlife Hospital to be hand-reared.

The females on Anchor Island have begun mating again.

And there is now breeding on three kākāpō islands, with Lisa the first female to mate on Hauturu/Little Barrier Island, near Auckland.

Lisa - the story of a 'missing kākāpō'

Lisa the kākāpō has a very interesting history. She is a founder bird from Stewart Island. She was first found as an adult in 1982, and then in 1992 she was moved to Hauturu / Little Barrier Island. Soon after her arrival her transmitter stopped working - and she disappeared.

Kākāpō are really well designed for going off the radar - they have perfect camouflage to just blend into the forest. They hole up during the day to sleep, and they creep around at night minding their own business. Put them on top of a rugged island with lots of steep- sided, never-visited valleys and it is very easy for them to go undetected.

Lisa became one of the missing kākāpō. Maybe dead but possibly still alive.

In the late 1990s a decision was made to take all the kākāpō off Hauturu as they weren't being very successful at breeding. The plan was to concentrate all the females on Whenua Hou, so all the females had been removed, but not all the males. It was the summer of 1999 and the remaining males were booming.

Then one day, the DOC ranger found kākāpō mating sign in Ox's bowl. Special kākāpō tracking dogs were brought in and eventually they found Lisa - on a nest - with three fertile eggs. Then just to make things even better all three hatched and were female. This was good news as at that time there were lots of male chicks. Her daughters are Ellie, Hauturu (after the island). and Aranga.

Lisa was moved to Whenua Hou, and in two of the following breeding season Lisa was the first female into action, mating with Basil at Christmas. She has had six more offspring, including Tiwhiri.

We've already heard about Tiwhiri in the Kākāpō Files, as she was one of the first females to mate on Anchor Island this season and she's the mum of one of the first batch of chicks.

Grandmother Lisa is now back on Hauturu and has mated, probably with Jester. She mated with Jester in 2016 but laid infertile eggs so it'll be interesting to see what happens this year…

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