Rarest of the rare
Rowi are the rarest of the rare—a species of kiwi so critically restricted in distribution and breeding success that they were almost done for. But a last-ditch effort—codenamed Operation Nest Egg—has dramatically changed the fortunes of the most imperilled kiwi in the world.
There’s nothing left of Department of Conservation ranger Tracey Dearlove except her legs.
She’s pushed herself face-first into a narrow tunnel at the base of a fortress of fallen branches, which towers over the pair of us. According to Dearlove’s radio receiver, there’s a kiwi nestled somewhere within. Maybe two. The burrow, however, twists and turns out of her reach. She wriggles her way back out, long hair flecked with a corona of peat and dead leaves, and flips open a pruning saw. It’s not easy to reach a kiwi nest without widening the front entrance of its burrow or digging a new back door.
We’re trying to find Wheki, one of about 450 rowi, the rarest of New Zealand’s five kiwi species. Almost all rowi live here, in the Ōkārito Kiwi Sanctuary, near Franz Josef on the West Coast—11,000 hectares of podocarp forest designated for their protection in 2000. According to the radio transmitter attached to Wheki’s hock, or thigh, he was incubating an egg when his signal was last heard. If so, it’ll be number 60 of this breeding season, and the last.
Tracking him involves tramping loops through his territory, pausing now and then to lift a bright-orange aerial aloft. Wheki’s transmitter is set to a unique frequency, but its range is limited, requiring a line of sight from the aerial to his leg. Hills have a tendency to get in the way, and yesterday, Dearlove and I bush-bashed our way up and down ridgelines to a soundtrack of white noise.
It isn’t until mid-morning on our second day that the faint pips of Wheki’s signal emerge from the static. Dearlove points to the right, down a slope festooned with supplejack and a mountain of kiekie. “It’s a bit rubbish in there,” she says.
I’ve learned over the past couple of days that “a bit rubbish” is Dearlove’s term for ‘nearly impassable’. I haven’t yet found my ‘forest legs’, as the rangers promised I would, and so I plunge unsteadily in Dearlove’s wake through waist-high ferns so thick I can’t see the ground. It’s like wading through a deep green pond.
Everything seems damp and decomposing. My feet sink through the trunks of fallen, rotting podocarps, and when I reach out to a ponga to steady myself, it topples over at my touch. In places, the ground is completely carpeted with moss, neon green and springy, silencing our steps.
The pips of the transmitter become louder the closer we get to Wheki, fainter if Dearlove points the aerial the wrong way. It’s like playing a game of Hotter/Colder inside an obstacle course.
Although the signal is inexact, occasionally leading us in circles, it’s a clever piece of technology. Every ten minutes, it broadcasts a series of pips encoding information: whether the rowi is alive, dead or incubating an egg, how long it has been in that state, its feeding behaviour, whether a chick has hatched, how old the chick is, and the battery life remaining on its transmitter.
Pip pip pip pip pip pip pip pip pip pip, says the receiver, and Dearlove pauses to listen. “He’s not incubating,” she says, and my heart falls. “But he only stopped a day ago.”
Does that mean we’ll find a chick instead? Dearlove doesn’t think the egg is old enough to have hatched—it’s still two weeks short of its 78-day incubation period—but we won’t know until we find Wheki’s burrow.
When the pips reach maximum volume, we know he’s just a few metres away, and Dearlove switches off the receiver. The glade falls quiet, the February air thick and barely stirring. It’s marshy underfoot, supplejack vines tangling in the air like party streamers. I eye up the stumps and fallen branches around us, wondering if a pair of sleeping kiwi—a little family, even—are concealed within.
Ōkārito Kiwi Sanctuary is silent because the stoats and rats within have dealt to most of its bird life. While adult kiwi can hold their own against them, their young don’t stand a chance. In 1995, there were around 180 rowi remaining, a population of ageing adults. Rowi still exist largely because they’re long-lived—up to an estimated 80 years—whereas a bird with a shorter lifespan could have vanished before we took notice.
The Department of Conservation tried trapping in the sanctuary, but it didn’t help. The solution was to rescue eggs from kiwi parents and hatch them in captivity—a programme codenamed Operation Nest Egg, which had proven successful with other kiwi species since its genesis in 1995. But there was a second component, too: raising rowi chicks in a predator-free environment until they reached their adult weight.
That place is Motuara Island in the Marlborough Sounds, more than 400 kilometres from Ōkārito. Less than two kilometres in length, the island has transformed the rowi programme. “It was the breakthrough that we were looking for,” says Chris Rickard, who led the rowi team from 1998–2002. “We went from very poor survival to damn near 100 per cent survival. Prior to that, we were trying to captive-rear, and that wasn’t a happening thing.”
So little was known about the rowi—it was described as a separate species only in 2003—that the team had little to go on except trial and error. “When we started doing the Operation Nest Egg programme, at that stage we knew nothing about the birds. We didn’t even know whether they had family groups,” he says. “I don’t think anyone had seen a chick survive for more than three weeks. No one had seen a sub-adult, so we didn’t know what was normal. We had pretty huge losses until we worked out a few issues.”
In the Ōkārito forest, rowi chicks are slow to put on weight, its gravelly moraine soil low in nutrients. Keeping chicks captive for months on end, however, had unintended consequences. Young rowi wouldn’t learn an appropriate sense of personal space, for instance, and on their release, would be killed by other rowi defending their territory. By contrast, Motuara’s uncontested buffet of worms and invertebrates nurtures chicks to fighting weight in less than a year, in a wild environment. “I think we’ve cracked the code with rowi,” Dearlove told me.
In the 2015–2016 breeding season, spanning July to February, the West Coast Wildlife Centre in Franz Josef hatched a total of 59 rowi chicks, compared to just one chick hatched in 2005–2006. Last October, 50 juveniles were transported from Motuara to Ōkārito, boosting the rowi population to more than 450.
Motuara Island, near the mouth of Queen Charlotte Sound, is unwelcoming: steep-sided, no beaches, a jetty that says ‘No berthing’. There’s a single public track up to the island’s ridgeline, which is visited by a handful of people each day, but otherwise it’s left alone.
As a result, Motuara is a paradise of birds. The bush thrums with the whirr of flapping wings, just out of sight. Tiny South Island robins hop up close, friendly and fearless as fantails, then belt out their song at the volume of a car alarm. Saddlebacks go vroom, vroom, like a kid with a toy car. Night doesn’t bring silence, but fluttering shearwaters cackling like monkeys as they wheel around the island and crash-land in the bush.
I’m holding a rowi in the crook of each arm like a pair of rugby balls. The trick is to grip them by their hocks and hold on tightly as they wriggle and twist, keeping their claws as far away from me as possible. Kiwi dog Rein, a Hungarian Vizsla, led us to the log they were sleeping beneath, and now I’ll carry them back to our home base on the island to reset their radio transmitters.
This pair don’t put up much of a fight. They soon stop struggling, flop over my arms and appear to fall asleep, their eyes drifting closed, but I can feel their heartbeats motoring away.
Their feathers, more like fur, are downy and warm, but their scaled, reptilian, dinosaur-like claws are another story. A third of their body weight is in their legs—powerful muscles and marrow-filled bones, unlike most birds, which have hollow bones to make them lighter for flying.
Whiskers sprout out of their faces, thick and black and bent in all directions, giving them an eccentric, startled look. The one curled over my left arm has white markings over his forehead—a genetic trait unique to rowi. The other rests its head in the crook of my elbow and sticks its cold, damp bill into my armpit.
Contrary to popular belief, their bills are blunt and very delicate. They’ll never fight with them, but sometimes they’ll blow saliva or bubbles out of their nostrils.
The hem of my black singlet is now a silvery slick of kiwi excrement. All day I’ve been crushing kawakawa leaves between my fingers to try to mask the metallic, ammonia-like smell on my hands, but it persists. No wonder they’re so easy for Rein to find.
The rowi start wriggling again when DOC intern Maddie Hansen searches through their feathers for the small triangular flaps of skin on each side, vestigial wings, under which their microchips are embedded. My fingers ache from holding their legs, and these aren’t fully grown birds—they’re just a few months old.
Rowi have to be a certain weight before they’re set free on the island. “We aim for 800 grams in size,” says DOC ranger Iain Graham. “If they’re over that, they’ve had a chance to figure out that they’re nocturnal animals and they should only be wandering around at night. We had a problem with rowi chicks day-walking and being predated by falcons. In the natal burrow, the parents may stop them going outside during the day.”
The 50 rowi released on the island this summer will be recaptured and returned home to Ōkārito in the spring. Their radio transmitters will be removed from their legs, freeing them from regular check-ups by Graham and Dearlove—until they reach breeding age, at about five years old. At that point, DOC rangers track them down again, but since the rowi are no longer broadcasting radio signals, it’s a different kind of hunt. It takes place in winter, at night.
Chris Rickard lifts his shepherd’s whistle to his lips and makes a series of loud, ascending calls. These are interrupted and echoed almost immediately. There’s the sound of motion in the undergrowth a couple of hundred metres away. Rickard has wandered into another rowi’s territory, and now, he’s picking a fight.
A few paces back, Grant Maslowski holds his breath and readies himself to catch a sprinting bird. It’s a moonless May night, and he can barely make out shapes in the darkness. The forest feels claustrophobic to him, the bushes pressing in close.
Rickard and Maslowski are hoping to catch an adult male to add to the Operation Nest Egg programme. If he has a mate, they’ll attach a radio transmitter to him in the hope of lifting eggs from the pair in the spring.
In his interview for a job on the rowi programme in the mid-90s, Rickard was asked if he could coax a kiwi call from a shepherd’s whistle—a circle of plastic or metal folded over on itself, leaving a small gap between the two halves. “I said yes, but I couldn’t,” he laughs. “The first thing I did was buy a shepherd’s whistle. It’s the same one I’m still using.”
Rickard, now an Ashburton crop farmer, remains a kiwi impersonator for hire. Not a single winter in the past 20 years has passed without him returning to the West Coast to catch kiwi—both rowi and its neighbour, the Haast tokoeka. The night stakeouts were always his favourite part of the job; he likes the challenge of reading the mood of a bird and trying to converse with it, drawing it ever closer to his landing net. “Like any conversation, you’ve got to listen to how the other party is responding,” he says. “I try to let them lead it.”
Even so, he can imitate only the male’s calls—he carries a recording of the female rowi’s cry on an MP3 player as a back-up tactic. Much easier than rewinding cassette tapes to the right spot, like in the old days.
Rickard’s been doing this for long enough that he’s well acquainted with the birds in the sanctuary and their various personality quirks. He knows which birds will walk into his net every time and which are the hardest to dupe. “Kiwis that have never been caught are much easier to catch than one that’s been caught a few times,” he says. “Some of them are absolute suckers for it, and then there are some in Ōkārito that I’ve missed five years in a row.”
The call of the rowi can sound like anything from a sharp whistle to an exaggerated horror-movie scream, and it’s hard to listen to without imagining something gruesome. It’s not yet known exactly why they call—perhaps to announce themselves, to delineate their territory, to find each other in the dark.
Suddenly, there’s a grunt and a guttural screech right behind Maslowski. It’s the female of the pair—larger, louder, less musical and more aggressive than her partner. Though the most damage they can inflict on a human is scratched legs, Maslowski stands completely still, hoping she’ll mistake him for a tree and not distract her mate from the hunt.
Rickard calls again in an attempt to entice the male to approach, and it works—the male charges, Rickard swoops, and the female retreats. There’s no transmitter on the male’s hock, so Rickard and Maslowski affix one and let him go. In the spring, there will hopefully be an egg to collect, maybe two.
The egg glows red where Kim Bryan-Walker holds a candling torch against it. I can just make out the pink blur of a bill touching the inside wall of the shell, like a finger pressed against fogged glass. Red means it’s healthy. A translucent area indicates the air sac, which increases rapidly in size as the chick prepares to hatch. There’s the veiny texture of the egg’s three-layered membrane, then at the base of the shell it’s black—the yolk sac, which is connected to the chick’s intestines through its navel. After the six-day effort of hatching, the chick spends its first 48 hours barely moving, weighed down by the sac, which forms a quarter of its weight. The yolk’s nutrients are absorbed into the chick’s body during its first week of life. “At first, they won’t even stand on their own two feet—just shuffle,” says Bryan-Walker. “Hatching is a really sweaty process, so a stoat could easily follow that odour. I can come in here in the morning and I can smell if a chick has hatched overnight.”
What does rowi sweat smell like? “Wet dog,” she laughs.
The second egg has a tiny fracture, or external pip, which looks like paint peeling off a wall. Chicks use their neck and back muscles to push through the top of the shell, popping it off like a lid—they don’t have an egg tooth, as other birds do, to speed them along. The final emergence is so quick that Bryan-Walker estimates she’s witnessed just a dozen appear from the shell, out of the 300 or so that she’s had in her charge.
Bryan-Walker switches the lights on and whistles loudly at the two eggs, the swift ascending call of the male, then drums on the table with her fingertips. A moment passes, then the eggs begin to tremble, wobbling slightly off centre. This is the sign that all is well.
If there’s no response, something’s gone wrong. Bryan-Walker has to help around 20 per cent of chicks to hatch. “That’s 20 per cent that wouldn’t make it, right at the outset,” she says.
When an egg is lifted from the wild, there’s a long, heart-stopping wait to get it back to the West Coast Wildlife Centre to have it candled and find out whether it’s fertile.
Sometimes hours of bush-bashing, digging and crawling in the dirt end in disappointment when the candling torch shows no red glow, but pale yellow—an infertile yolk—or dense black—a rotten or infected egg.
Bryan-Walker carefully places the eggs back in an incubator, which is programmed to 70 per cent humidity and slowly turns the eggs this way and that. It can fit 200 chicken eggs or 15 kiwi eggs—but today it’s near the end of the breeding season, and there are only two still to hatch.
Four one-week-old chicks are in the adjoining room: Goldberry, Rickman, Wuzzle, a rowi/little spotted kiwi hybrid (see sidebar, page 39), and one still waiting for its name. They look, and sound, exactly like children’s toys that can be squeezed to make a noise. Bryan-Walker monitors each daily to make sure it’s putting on weight and has figured out how, and what, to eat. Chick feed—a mixture of minced ox heart, cat biscuits, wheatgerm, currants, peas, carrots and corn—doesn’t twitch and squirm like the rowi’s usual diet of invertebrates, and sometimes the West Coast Wildlife Centre staff have to pick up bits of food and wiggle them so that the chicks know what to do. When chicks are very young and still figuring out what food is, they’ll even eat dirt. Mostly, though, they come pre-programmed—Goldberry, Rickman and Wuzzle already know how to be kiwi. On their release, they’ll need no assistance finding food, or a burrow, or a mate.
“We really hit a milestone this season: we had our first second-generation chick,” says Bryan-Walker. Its parent, caught by Rickard over the winter, had a microchip under its wing, meaning it, too, had been reared in captivity. “It really brought it home to me—this chick would not have existed if we hadn’t worked with its parents.”
Each egg hatched is one step closer to putting Bryan-Walker out of a job. When the Ōkārito population reaches 600 birds—which the programme is on track to do by 2018—and the chick-survival rate lifts to 25 per cent, then the rowi will be self-sustaining enough to call an end to Operation Nest Egg in Franz Josef.
But this is an ambitious target. Without the captive breeding programme, rowi chicks have a survival rate in the wild of just five per cent. And the 70,000 kiwi in New Zealand are currently declining at a rate of two per cent per year—or 27 birds a week.
Raising the survival rate of rowi chicks to improve on this national average would involve predator control being reintroduced to the forest—another puzzle to solve.
“What would it take to reverse that two per cent decline?” muses Iain Graham. “You can’t really let them disappear, no matter how hard they try to.”
“I can see them in there,” says Tracey Dearlove. She tapes a metal crook to the end of a metre-long stick and dives headfirst back into the burrow. Wheki and his mate within don’t seem to be concerned about the commotion we’re making at their front door—they’re still sleeping.
“Some rowi will hear you coming from 10 metres away and start running,” she told me earlier. “Others are much more chilled out, and you can practically reach between their legs and remove an egg.”
Dearlove finally manages to hook Wheki out of his burrow, blinking and wiggling.
His feathers are stiff, crusted with dirt. He wasn’t sitting astride an egg—Dearlove assumes that it failed, which explains the shell fragments she found mixed in with the dirt.
There’s nothing for it but to change Wheki’s transmitter and move on to search for other rowi in the area. All birds with transmitters are caught every year for a health check-up and a battery change, and now that the breeding season is over, the rangers’ attention will turn to this task.
We track down a male rowi whose eyes are covered by milky cataracts and whose humped head is starting to go bald, making it easy to see his enormous ears—oblong holes in the side of his head. He’s probably blind—not that sighted kiwi have much of an advantage over him. In contrast to other nocturnal birds, kiwi have small eyes, and the narrowest field of vision of any bird in the world. They can’t even see their own bills, foraging instead by their sharp senses of smell, hearing and tactile sensation. A feeding rowi paces the forest, hovering its bill above the ground, or gently tapping it, like a blind person with a cane.
This male lies peacefully along my arm while Dearlove checks his skin for parasites. When she places him back at the entrance to his burrow, he shuffles slowly within. This is what people imagine kiwi to be like, gentle and shy and shambling. It couldn’t be further from the truth.
We pick up one more signal before the end of the day, tracking it to a hollow log in a marshy valley. When Dearlove reaches inside, there’s the sound of a scuffle and she lifts up a huge, writhing rowi by the hocks. Its size means that it’s a female.
She’s so strong that I struggle to hold her—she slips a claw loose from my grip and sinks it into my hand like a knife through butter. Unlike the other rowi I’ve handled so far, she doesn’t relax while we change her transmitter. When Dearlove returns her to her log, she takes off at a sprint, leaping over fallen branches with surprising fluidity, beak low to the ground.
Seeing her run through the forest, I become a little unmoored from the present day. Watching her is a window into the Ōkārito of millennia past: a hunched, furred silhouette dashing through the shadows, three-toed claws sinking into moss, running through territory that she will defend by night with spine-chilling screams. Is this really just a ghost of the past? Or a vision of the future, too?