We’re on the front lines of the Save Our Iconic Kiwi initiative. This is the sixteenth in a series following the work being done to save the Fiordland tokoeka (kiwi). Our ranger Tim and his team have been studying the population of kiwi at Shy Lake to find out how to best protect them from predators like stoats. They have captured a number of kiwi and put transmitters on them, and are now monitoring them through the breeding season to find out how well the adults and chicks survive without pest control.
Today’s guest post come from writer and filmmaker Peta Carey. Peta is writing a book on Dusky Sound and headed out to Shy Lake a few weeks ago.
The last time I heard kiwi calling in Fiordland was the early 1980s, from the cliffs above Pyke River in the Hollyford Valley. It’s a sound we should all know, every New Zealander should hear. So to sit with Tim Raemaekers and his co-ranger Anne, waiting patiently outside a nest site near Shy Lake in Fiordland this last month, and hear the distinctive high pitched call of the southern Fiordland tokoeka, put a smile on my face.
It also woke me up. I was nodding off, even in the bitterly cold night. Sitting on a mossy bank I’d almost fallen off my perch. It was 10.30pm and Tim and Anne had been patiently watching the nest entrance since before dark. Tim had repeatedly told me to bring plenty of warm gear. I had watched them ‘layer up’ in down jackets, at least two warm hats and multiple layers of gloves. And Tim had even carried a hot water bottle down from the bivvy, tucked up inside his jacket.
So there was the cold. But there was also the wait. What strikes you about this work is not only the physical extremes these rangers go to (requiring Godzone-rated-fitness levels, up and down mountains), but also the extraordinary patience the research requires. I’m simply here as a casual observer, documenting the project for a book about Tamatea/Dusky Sound. I’m already in awe of the team’s dedication and perseverance, my levels of patience shamefully low as eyelids droop.
Behind me T-Rex is calling out, proclaiming his territory. He’d left the nest an hour earlier, leaving his now week old chick behind, alone. And Tim and Anne are watching for the chick to emerge, to then be able to carefully fit a small transmitter to the new addition.
Checking T-Rex trailcam. 📷: Peta Carey
It’s been a long day, and Tim’s getting cold and tired too. He finally extends one arm into the burrow of the nest – yes, the chick is within reach – and gently extracts the small ball of fluff. Head torches on, the process of beak measuring, weighing and transmitter-attachment is gentle and efficient, before Tim returns the chick to the shelter of the nest.
If you’ve been reading Tim’s excellent blog, you’ll know that he was here the previous summer, doing just this. You’ll have followed the story of how T-Rex and his female partner T-Regina, had a chick that disappeared, along with its transmitter, into what Tim had supposed was a stoat’s pantry, deep within the labyrinth of tree roots.
One year on, Tim’s here again. Another spring/summer of hope. But this research is simply a mortality game. Last year Tim optimistically gave some of the chicks names. This year he advises not to, suggesting no one should get attached to any offspring. It could well be a repeat of last year’s survival rates. None made it.
It’s past midnight before we get back up to the bivvy above the bush line, just before the southerly storm, or rather blizzard, hits. ‘Celmisia Lodge’ is well tied down, and it’s a furious white world the next morning.
Celmisia Lodge in the southerly blast. 📷: Peta Carey
Reviewing trailcam footage. 📷: Peta Carey
More extremes. Crikey, these rangers are tough. But not foolhardy. While Tim heads down valley to a nearby nest between squalls, Anne weighs up the risks associated with thigh-deep snow and furious wind on the ridgeline to reach another nest. Not today. There are motion-sensored trail-cam videos to watch – endless images of kiwi coming and going from the nest – but also kea, weka (getting a good hiding from resident adult male kiwi) and the stark repetitive images of the evil slink of the stoat.
It’s still snowing lightly, but not blowing, when Tim and I head out the following day to the area above Sinbad’s Staircase track. First base is Pegleg’s nest and most of the day is taken up with Tim looking for Pegleg’s chick, which is not in the nest.
Tracking a kiwi chick. 📷: Peta Carey
The previous summer, Pegleg and Patch’s first chick had failed to hatch, and a second, later in the summer, failed to come home on only its second night out of the nest. It’s heartening that the adult kiwi don’t give up, that instinct decrees that year after year they continue to produce eggs, incubate them for around 75 days, and nurture the chicks for however long before reality, err, bites.
The hope is that help arrives before the surviving adult birds are too old to reproduce, or that sufficient chicks make it past the six-month mark (when they’re strong enough to fend off a stoat), to ensure the population continues. Common sense tells you that if that’s going to happen, we need to somehow get rid of the mustelids.
Tim finally found Pegleg’s chick. He’d had to scale another section of the bluff that lies a few hundred metres below the nest. No, the chick had not washed down the stream by the nest (as Tim had speculated), but the remnant feathers and transmitter were laid down with the remains of various small birds within a stoat den. Pegleg’s un-named chick had gone the way of the rest.
As Tim’s explained, this ‘mortality game’ research is not simply to watch southern Fiordland tokoeka decline, but to ensure there is scientific rigour – not just a wild guess, but definitive and robust results of chick mortality, numbers and cause of death, before and after predator control. The end game? To assess whether a decent dose of 1080 will make a difference to the stoat population, meaning chick survival rates might improve.
The beech trees (and rimu and various other species) are set to ‘mast’ this summer, meaning a bumper season of fruits and seeds, and a resultant spike in rat numbers. The rats don’t bother the tokoeka, the stoats do. And although stoats won’t touch the 1080, being carnivorous, they will scavenge on rats. So if all goes to plan there’ll be a good number of rat carcasses lying around to ensure a 1080-laced banquet for the stoats.
Next summer, 2019/2020, Tim is expecting to be able to track chicks beyond the two-week mark, and beyond. If that’s the case he’ll know that 1080 could well be the saving grace for one summer’s generation, at least.
In the meantime the work Tim and his team are doing – arduous, demanding a high level of skill and dedication – is enormously valuable. Not only will the research present a reliable comparison of before and after predator control, but it will add to our understanding of the behaviour and biology of one of the most extraordinary birds on the planet.
Aye, we’ll need more tools than one aerial drop of 1080 to ensure a sustainable population of southern Fiordland tokoeka on the mainland. But for me, it’s a case of buying time, using whatever we have in our arsenal against mammalian predators before our taonga, tokoeka being one of them, are gone – along with their plaintive call, the sound of the New Zealand forest we should all be able to hear, at least once in a lifetime.
This is the sixteenth in a series of posts about the Save Our Iconic Kiwi initiative work at Shy Lake, follow the Conservation Blog to keep up to date on his progress.
