Four kakapo chicks are being hand-reared in a DOC "safe house".
A tin-roofed, weatherboard house in one of Nelson's quiet suburban streets is harbouring four refugees. The authorities are keeping the location of the house secret and the refugees aren't allowed out the door.
Nelson is used to secretive guests - Bill Gates is rumoured to be a regular visitor - but in this case there's nothing sinister at play. The town is playing host for the winter to four of the world's remaining kakapo, the world's heaviest parrot. The chicks are being hand-reared in a Department of Conservation "safe house".
The "Nelson Four" answer to the nicknames Dit, Dot, Zoe and Pukunui. A fifth chick, Jem, died after a few weeks in the house, of hepatitis. Kakapo chicks are especially vulnerable to infection because of in-bred weaknesses caused by their tiny gene pool. The survival of the other chicks is a significant boost to the species, however, which still totals just 87.
So crucial is the survival of these chicks that, in April, DOC removed them from Whenua Hou (Codfish Island) in a helicopter. After their trip to Invercargill, two DOC staff carried the chicks in special bird boxes on commercial flights to Christ-church and Nelson, each carer with a bird box resting on the seat beside them.
The suburban kakapo kindergarten consists of a gloomy, humid basement room in a nondescript rental home. The VIP guests live in large pens, their floors covered in green towels. A sparse bit of foliage is a small reminder of home. One pen contains two female chicks, Dit and Dot. They have wide faces, broad bills and luminous olive green and yellow plumage.
Even at 45 days old, Dit and Dot have massive claws and surprisingly big wings - which they flap frequently, apparently for balance as much as display. Another pen contains Pukunui. He is male, heavier, and quarantined until a recently treated wound has fully healed.
DOC's decision to move the chicks has puzzled some people - why spend years making three islands - Whenua Hou, Te Kakahu (Chalky Island) and Pearl Island - predator-free, only to move the chicks to an environment full of cats, stoats, rats and worst of all, humans?
DOC technical officer Daryl Eason explains: "It's for several reasons, not least the weather. These kakapos mainly eat the fruit of the rimu tree. This year's crop was good enough to encourage breeding to take place - but not good enough to guarantee the chicks' survival.
"Kakapos are flightless, but a mother bird will climb 20 metres up a tree to get food. The higher she climbs, the more food she needs to replenish her energy levels and the longer the chicks are left unprotected."
Unprotected? Although the islands are predator-free, testosterone-charged young adult males will try to mate with "anything with feathers on", even a male chick.
"In the wild, the chicks are weighed daily," says Eason. "Once they dip 20 percent below their expected growth rate, a survival plan is triggered."
Previously, kakapo chicks have been hand-reared at DOC's Te Anau centre in Fiordland, but since the last breeding season, Eason, and Gideon Climo, another key kakapo team member, have started families in Nelson. This made the logistics of living in Fiordland for four months much less practicable.
"Birds are still easier than 20-month-old boys," says Eason. "You can feed kakapos exactly when you want and you can get time off from them!"
Asked about the dangers of human intervention, Eason emphasises DOC's cautious approach. "Some chicks seem to enjoy human contact, but we need to avoid the danger of 'imprinting' them - where a chick thinks its parent is human. This can cause breeding problems in later life."
But the team don't think their intervention had anything to do with Jem's death. Dr Ron Moorehouse, one of the team's scientists, says, "The sterility of the birds' environment in transit and here in Nelson makes infections less likely than in the wild."
Yet the birds must head home soon. In June, the chicks will have tiny radio transmitters fitted and be returned south. By then, they will have a need to "get out more", experience weather, real vegetation and revert to being nocturnal.
The four chicks on holiday in sunny Nelson are probably the first kakapos for hundreds of years to enter a human settlement with a strong chance of actually surviving the visit.