It's kakapo mating time, but as Kerrie Waterworth explains, this is not your usual tale of the birds and the bees.
The pursuit of love is not easy for a male kakapo, though they are one of most highly sexed birds in the world, according to veteran New Zealand wildlife photographer and writer Rod Morris.
In the early 1970s, Morris accompanied Don Merton, of the former New Zealand Wildlife Service, on an expedition to find kakapo in Fiordland.
Merton took the first black-and-white photographs, while Morris took the first colour stills of the world's heaviest, only nocturnal and flightless parrot making its unique booming mating call.
In 1986, Morris returned to photograph the last remaining mainland kakapo, 13 males. All had climbed as high as they could to get away from stoats and were living on glacial mountainsides.
He found them extremely frustrated and trying to mate with sticks, branches, dead birds and even wildlife photographers.
For the past 30 years, recording the elaborate mating ritual of the kakapo, now all living on predator-free island sanctuaries, had become the "Holy Grail for wildlife photographers", Morris said. On February 18 last year, at 5.50am on a windy but dry morning on Codfish Island/Whenua Hou, a sanctuary 3km off the coast of Stewart Island, cameraman Scott Mouat cracked it.
"Cyndy, a female kakapo, had been coming and going all night long, and by 5.30am she came in close to Ox, the male, but then she left.
I thought that was it and switched off the receiver that had been picking up signals from Cyndy's transmitter backpack.
"Fifteen minutes later, Ox dashed off his bowl [a depression scraped in the dirt]. I thought he was just playing silly buggers as they do at that time in the morning, but when I swung the camera round I could just make out the shape of Ox mating and the outline of a female underneath," he said.
Mouat (35), a graduate from the University of Otago's postgraduate diploma in natural history film-making course with only three years' professional experience, is making a feature-length documentary on the kakapo. He had allowed four weeks to record the mating, which happened on the 26th night.
"Every night from 9.30pm to 6.30am, I stayed in my hide and waited. It was only about a metre and a-half square, so I had space to sit up, but that was it. I'd sit on a plastic case with a bit of foam on it, camera in front of me, legs tucked under the tripod and with the camera on all the time. I had a waterproof cover for the camera if it rained, as the hide was not always waterproof, but it was the wind that was the worry.
"I was lucky that there was only one night when it blew its heart out, and I was glad the hide was tied to the vegetation," he said.
Scott used a high-definition infrared camera, one of only two in the world, borrowed from Japan's national broadcaster NHK.
He said the kakapo were wary of lights.
"The kakapo are very scatty . . . I was only about five or 10 metres from the birds, so I had to stay perfectly still and try not to make any noise.
"I only had the image from the infrared monitor, the noise of the kakapo and the constant drone of seabirds overhead to tell me what was going on outside. . . .
"I had the continual beeping in my ear from a receiver picking up signals from kakapo backpack transmitters telling me which birds were where on the island, which helped to keep me awake," he said.
Rod Morris first heard the mating call of the male kakapo in Fiordland.
"Kakapo are unique in that they are the only lek bird species in New Zealand. That's where the normally solitary males congregate and boom across vast distances calling for a mate."
He said they would call for hours.
"We also had a number of individual males dance to us, coming down their tracks very slowly and deliberately with wings fully extended waving up and down like a butterfly and making a clicking noise at the same time," he said.
Thirty years later, Mouat captured moving images of the kakapo mating for the first time.
"It's a balance that you've got to be far enough away so the bird isn't bothered by you but near enough to film them in the dark.
"They've this got this track and bowl system where the male makes a bowl shape in the dirt and clears a series of tracks leading to and from it. He puffs up an air sac in his throat and makes this deep subsonic booming noise.
"No-one really knows the reason for the bowl but it's thought it may help the sound to carry several kilometres away. The males alternate between the booming and a kind of chinging sound almost like a giant cricket which helps the female pinpoint exactly where he is," Mouat said.
Kakapo once roamed freely throughout New Zealand. The species evolved into feeding at night to avoid being attacked by its only known predator, the Haast eagle, and learned to climb trees to hide during the day. Its moss-green, yellow and brown plumage camouflages it so well that you could be standing near one and not see it.
But since the arrival of humans, dogs, cats, stoats and rats, the kakapo has had to retreat to increasingly remote areas. From 1949 to 1973, the Wildlife Service made more than 60 expeditions to find kakapo, focusing mainly on Fiordland. Six were caught, but all were males and all but one died within a few months in captivity.
The last surviving Fiordland kakapo is Richard Henry, named after an early champion of native birds who between 1895 and 1908 relocated nearly 600 kakapo to Resolution Island in Dusky Sound. Sadly, by the early 1900s stoats had swum to Resolution Island and within a very short time the kakapo were gone.
Richard Henry now lives on Codfish Island and his three progeny are the last link to Fiordland genetic stock.
Today, kakapo live on two predator-free islands - Codfish Island and Anchor Island, Dusky Sound. Though suitable as long-term sanctuaries for kakapo, the islands are not big enough to support a population of more than 100 birds.
About 60 kakapo live on Codfish Island, managed by Department of Conservation (Doc) staff and volunteers. The Doc kakapo breeding programme is aiming to have 150 breeding females by 2016 but there is no predator-free island big enough for the kakapo to be self-sustaining and to look after themselves.
Surprisingly, the greatest threat to the continued survival of the kakapo on these island sanctuaries is now Mother Nature. On Codfish Island, females mate only when there is enough rimu fruit to raise chicks.
The late summers of 2002, 2005 and 2008 had a bumper crop of rimu flowers and fruit, resulting in the birth of kakapo chicks, but in 2003, 2004, 2006 and 2007, not enough rimu trees flowered and no eggs were laid. This summer, kakapo programme manager Deirdre Vercoe says they are hoping for a high percentage of trees flowering, which would mean a lot of fruit.
The other major threat to kakapo is genetic diversity.
At the end of this month, Spanish artificial insemination expert Dr Juan Blanco will spend two weeks with the Doc kakapo team to demonstrate how to extract kakapo sperm by massaging, and how to store it.
The team has found artificial insemination provides greater control over the gene pool. The females can copulate more than once, which gives them a higher fertility rate, and the team can determine which sperm fertilises an egg.
"Juan is quite spiritual in the way he massages the birds. He kind of asks permission of the birds and he seems to have a calming influence. He's been training Daryl, another kakapo recovery team member, and myself how to do it and we've been practising on domestic roosters," Vercoe said.
"I've been artificially inseminating birds for 20 years but the kakapo is unlike any other bird I've worked with. For a start, it's flightless, which means . . . it is similar to mammals in its way of walking, its heavy bones and feeding etc.
"I have to approach kakapo in a different way, as it is so synchronised with its habitat that one could say it is perfect harmony with the earth that it makes it special and powerful in many ways," Blanco said.
When not sleeping during the day, Mouat filmed Blanco collecting sperm and analysing the sperm count.
This last summer, they artificially inseminated only one female because they have to meet certain criteria.
If a bird lays eggs within six days of mating, the eggs are almost always fertile, but if she does not, she becomes a good candidate for artificial insemination. That way, the kakapo recovery team can make sure they get not only fertile eggs but also a genetically diverse father, ideally one of the Fiordland lineage.
Their goal was to increase genetic diversity within the population, wherever possible using the Fiordland kakapo's genes, he said.
Mouat is one of what Morris describes as the new breed of natural history film-makers.
"In the early days, there were groups of us making a programme. Now, it's so expensive you've got to be a jack of all trades, make the film single-handedly, write your own scripts, film it, record the sound and edit it.
"He's pretty extraordinary: not only was Scott filming at night but he was having to keep his electronic camera equipment dry in one of the wettest places in New Zealand.
"I believe Scott has tackled probably the most difficult story there is in New Zealand today - filming the mating of the elusive kakapo.
"We used to think the kakapo was a gentle, clumsy, peace-loving bird, but thanks to Scott we now know the males have terrible fights and can inflict awful injuries on one another. They're also not as romantic as we once thought, rushing at the female and beating her about the head with his wings as he mates," he said.
Scott is now editing and expects his film - with the working title of The Code of Kakapo - will be completed by April.
He funded it independently to retain artistic and creative control but is not confident of finding a buyer and has already been knocked back by one of New Zealand's main TV networks.
"It frustrates me, because I think television has a bigger responsibility than just making money. If they don't show natural history, if they don't tell these stories, then people aren't going to fully appreciate what we have. I think there's a much bigger responsibility for television to step outside that money-making, advertising medium and show stories like the kakapo, stories that people need to be shown," Mouat said.
Scott's working relationship with the kakapo is continuing. He is back on Codfish Island filming the kakapo for a sequence in a major international TV series for NHNZ.
As the ODT went to press the rimu trees were flowering but it was too early to say whether they were going to have a bumper crop of fruit. Four females have mated successfully, and one bird, Lisa, has laid three eggs, though one was infertile and one embryo died. Doc workers are optimistic about the third egg.