Great Barrier Island Environmental News
Home                Newsletters


Beyond Barrier - conservation dogs and the war on rats
aka the adventures of Milly (Part 2)

by Scott Sambell

In this multi-part series, Scott Sambell recounts his recent journeys with Milly to some of our very special offshore islands, and we see a glimpse of past (and future?) New Zealand ...


Mangere Island

Mountaineers have Mt Everest, musicians have Abbey Road, and rugby fans have… well Rugby (the town), I guess. Conservationists, such as myself and my mobile olfactory companion, Milly, have Mangere Island.  The staging place of the greatest story in the history of conservation – ever.

The tale of Mangere Island, its avian inhabitants, and the people that saved them – literally – from the brink of extinction – is legend. Like all conservationists, I have seen many images of the imposing rocks of these two islands taken from all angles as I have pawed through the many iterations of ‘the story of Mangere’. I had assumed, that had I ever been within leaping distance of those rocks, I would be filled with awe and excited anticipation. In fact, as I stood holding on the rapidly ascending bow of the crayfish boat, my feeling was more akin to dread, fear, and a wickedly strong shot of motion sickness.

Getting ashore

No matter how many times you practice throwing your best friend over two metres of icy water onto a slippery rock shelf, it never gets boring.  But, true to form, Milly the rodent detection dog landed perfectly on all fours and, as rehearsed, trotted confidently five steps forward to avoid being crushed as I landed closely behind.

We were on Mangere Island to check for rats, to continue the protection of what was... the most endangered species in the world. 

The two of us, in our own little way, were now continuing the legacy of Mangere Island.  We were shortly joined by two Department of Conservation staff. Once the many buckets and barrels of supplies were safely ashore, we began the arduous process of lugging them across the rock shelf and up to the hut, somewhere amongst the towering cliffs above us. 

Mangere Island (right) and Little Mangere Island (to its left) - the setting for the planet's greatest ever conservation story.  Photo: Sarah Matthew

This tiny wind-battered relic of history would be our home the next four days, or as long as it took for the next break in weather to allow the boat to pick us up. It didn’t fill me with a lot of confidence that we had at least a week’s worth of food in the barrels and then to discover another two weeks’ worth of food in the hut… and fishing gear.

“This”, announced one of the staffers, “is nothing”, upon hearing my concerns – apparently two 44-gallon drums of food and supplies were buried on the hill above us – just in case the entire hut was somehow swept away.  I looked down at my offsider who was wagging her tail obliviously and informed her, “We are really remote this time buddy”.

Milly the conservation dog

For those that have only just joined us or weren’t interested enough in rats to read our Part 1 of this series, Milly and I, at this stage were half way through a tour of duty on the Chatham Islands archipelago, doing, what we have been doing all her life – looking for rats on pest free islands.

For Milly is a conservation dog - and good one at that.  She was bred, raised and trained to do only two things – obey my every command and find rodents. 

Let’s be clear, it’s not just any, off-the-shelf Jack Russel terrier that can go to the most sensitive ecosystems in the word and sniff around in the undergrowth. There are some very, very precious species on these islands that she must completely and utterly ignore on our adventures, and none is more precious and rare, than the infamous Chatham Island black robin/kakaruia (Petroica traversi).  The very thing that we had been sent to this island to help protect.

Milly the conservation dog.  Photo: Sarah Matthew

Black robin history

I found the four buckets with ‘Scott’ and ‘Milly’ written on them and lugged them into the bunkroom as I checked out the inside of the hut.  It was just as I imagined it would be, but real. On the walls, illustrated by some of the many scientists and legends of New Zealand conservation that proceeded us, were murals of the special birds they had been protecting.  We were in the place where the staging of the saving of the black robin had taken place... or at least I was. 

Milly was quietly whimpering outside as she is not allowed inside Department of Conservation huts. It wasn’t long though before I’d fished out her muzzle and coat and my oilskin coat and was out the door with my super-enthusiastic rat hunter bounding in leaps, several times her height along beside me. We were off to Robin Bush!

As with Rangatira Island, which we had left that morning, Mangere Island is home to tens of thousands of seabids, the burrows of which we carefully avoided as we picked our way up the path to the island’s main ridge. The prions and storm petrels weren’t at home – and wouldn’t be until dusk –  returning en-masse in a what can only be described as an extraordinary spectacle (unless you are the type of person that comes to remote sub-Antarctic islands expecting to get any kind of sleep!).

Once on the ridge, we turned south at the emergency supply depot and camp site and headed down to the bluff at the end of the island. Milly, with her head ever-pinned to the ground constantly scouring the undergrowth for the slightest hint of rat, didn’t notice when the monolith of Little Mangere Island came into view. She was still sniffing exhaustively when we had gone another 100m and I saw for the first time with my own eyes the infamous ‘landing beach’ on the north end of Little Mangere.

I admit, at this stage I swore loud enough for Milly to stop her incessant sniffing.  In fact, she even lifted her head and sat down in compliance, assuming I was telling her off. My words did explain very eloquently the courage needed to land a small boat on that point and free-climb the near vertical ridge above it. In 1976, this is precisely what Don Merton and his team did.

The world’s rarest bird

For four years prior, Merton and his team had been visiting the two Mangere Islands searching for species that had been lost on the mainland of New Zealand. And found them. Unfortunately, they found the last remaining black robins, just 18, in the world on top of a 100m high rock stock in a tiny patch of salt encrusted bush which was well on the way to becoming unsustainable habitat. 

They studied the birds, recorded their dwindling numbers and by 1976 concluded that direct intervention would be the only way to save the species. In September of that year, the team, nosed a 12-foot-long dinghy up to the only part of the island even remotely accessible, and climbed up the ridge with bird boxes strapped to their backs to begin an audacious translocation. 

All black robin alive today are descended from just one breeding pair - 'Old Blue' and 'Old Yellow', named for the colour of their leg bands.  Photo: Sarah Matthew

When they got to the dying patch of bush, they found only five birds and just a single breeding pair.

As I looked across from the ridge on Mangere Island to the summit of Little Mangere, I tried to imagine what was going through their minds when they discovered that one last pair.

Here were the Adam and Eve of the species.  All 30 grams of them. Their mission was to catch them, put them in boxes, climb down a sheer cliff into a tiny boat perilously colliding with the rocks below, transport the birds to a safe place and then, somehow, convince them to breed. 

Of course, we all know how it ends, and indeed, where it ended – in Robin Bush where we were headed next. I whistled and Milly was immediately at my side. “Go ahead” I said, and motioned at the track down to Robin Bush. Milly shot off in front, nose to the ground. I followed behind.

Black robins on the inside of the hut on Mangere Island - illustrated by some of the many scientists and legends of New Zealand conservation. Photo: S Sambell

Robin Bush

If you could pick one word to describe 90% of Mangere Island you wouldn’t go too wrong to choose ‘windswept’ or ‘salt-blasted’.  Just one tiny patch of bush, protected by a 200m high cliff on the eastern coast, looks like it could sustain forest life of some kind.

This is where Merton and his team decided to translocate their five birds (not that they had many other choices) and promptly built aviaries and bird boxes to give these tiny birds the best chance of clawing their way back from the brink of extinction.

Our main task was to search Robin Bush because, for reasons which should be too obvious for me to go into, rodents like to live where birds like to live which is precisely why it is so important that we don’t allow them to.

We spent the rest of the day (and most of the rest of the week) scouring Robin Bush for signs of rodents. Well, Milly was scouring, I was far more interested in investigating the remnants of the old aviary, the bird boxes and of course the descendants of the last two breeding black robins. 

Unfortunately, it wasn’t just a case of leaving the birds to it when they finally delivered the birds to this patch of healthy bush on Mangere. Once the translocation was complete, Merton and his team created and instigated a foster parent program for the fledglings, to encourage the last pair to produce enough offspring to create a viable population. The method worked and the descendants of Old Blue are doing well. I’m not sure what generation these birds were, but there are now plenty of them.

Milly in Robin Bush - the small patch of forest on Mangere Island where the last black robins were translocated in a bid to save the species. Photo: S Sambell

Old Blue

As the bush began to grow dark and our stamina was fading, we slid off a boulder into a flat clearing, a rare treat on such a steep island, and I threw my pack to ground to recuperate for a moment. Milly took this as a cue for a power-nap and instantly curled up on my pack while I pulled out the map to plan the quickest route back to base. I realised then that the area I was standing in was more than a clearing, it was more like a natural amphitheatre. Now, a very special few of you reading this would have been to Mangere Island and ‘The Amphitheatre’, so you will have to bear with me, but for those that haven’t, read on.

This majestic little clearing, just large enough to very snuggly pitch two tents, is surrounded by large boulders that seem to stand sentry and bear witness to the very special thing that happened here 40 years ago. If you turn back towards the cliff above Robin Bush, you’ll see one particularly prominent boulder.  On that boulder, a human, has hung a plaque to let all those humans that came after them – myself included – know how special this place is.

I must have wandered too far from my pack because Milly took this as a cue to stand up and follow me and I looked back just as the great, great, great grandchild of Don’s robins flew straight over her head and on landed on the rock above the plaque. As Milly came along side and obediently sat down I read it aloud to her….

In memory of ‘Old Blue’

1971 – 1983

Last productive female 1979 – 1982

Ancestral mother of all black robins

Lived & bred here and

saved her species


It was indeed many days past the prearranged pick-up date when the boat finally made it back.  It gave us time to properly search the island and quite a lot of time in the little hut finding ways to kill time between the squalls battering its thin walls. For anyone who has spent time in the Mangere hut, you will know, like I do now, every inch of its walls and the many messages and drawings that its inhabitants have left there. If you ever find yourself in the same position, be sure to examine the architrave on the northern wall where the many visitors, including the late great Don Merton, have scratched a line to mark their own height and written their name alongside.  If you look down the bottom of the wall, you’ll see a scratch on the timber not more than 30cm off the ground, and alongside, the name of a brave little dog that has given her entire life to conservation – and she’s not done yet.

Next issue….Part 3’ll just have to wait and see!