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.

Go to this episode on rnz.co.nz for more details