Safe Haven for Young Kiwis

By Alina Suchanski

Reading time: 12 minutes

Once known for a deafening chorus of birdsong, New Zealand has been losing its native species at an alarming rate since humans colonised its islands. In recent years, efforts have been made to reverse this trend and protect the surviving native species. The Pomona Island Trust is doing just that. Alina Suchanski takes a trip to Pomona Island to see what has been achieved.

It’s a crisp, sunny morning in Fiordland as I board a Lake Manapouri water taxi with eleven Pomona Island Trust members and volunteers on their monthly trap checking visit to Pomona. It’s been the driest summer in recent years and the lake level is low; its calm waters revealing a few small white-sand beaches on the otherwise steep, rocky shore of the island. Twenty minutes later, we land on one of those charming beaches and wave the water taxi goodbye.

By Alina Suchanski

Reading time: 12 minutes

Once known for a deafening chorus of birdsong, New Zealand has been losing its native species at an alarming rate since humans colonised its islands. In recent years, efforts have been made to reverse this trend and protect the surviving native species. The Pomona Island Trust is doing just that. Alina Suchanski takes a trip to Pomona Island to see what has been achieved.

It’s a crisp, sunny morning in Fiordland as I board a Lake Manapouri water taxi with eleven Pomona Island Trust members and volunteers on their monthly trap checking visit to Pomona. It’s been the driest summer in recent years and the lake level is low; its calm waters revealing a few small white-sand beaches on the otherwise steep, rocky shore of the island. Twenty minutes later, we land on one of those charming beaches and wave the water taxi goodbye.

Pomona Island Trust members and co-opted volunteers on the beach on Pomona Island.
Photo: Alina Suchanski

Between 100 and 80 million years ago, New Zealand broke away from Gondwanaland and started to move toward its present position. Since that time, this small archipelago in southern Pacific has developed a unique flora and fauna. Humankind began to colonise the islands of New Zealand around 800 years ago. It was “a land where bush grew to the water’s edge and trees were filled from ground level to canopy with copious bird and insect life” (King, 2003).

During the relatively short occupation of New Zealand by humans, a large number of species have become extinct due to predation by introduced animals, hunting, and loss of habitat. Many remaining species are under threat because of past and ongoing human activities.

Conservation organisations began to form from the 19th century. An early conservation lobby group was the Royal Forest and Bird Protection Society of New Zealand, established in 1923, now the foremost environmental organisation involved in conservation advocacy in New Zealand, and these days known simply as Forest and Bird.

In 1987, the Department of Conservation (DOC) was created by merging the conservation aspects of three governmental bodies: the Forest Service, the Department of Lands and Survey, and the Wildlife Service. Today, DOC administers approximately 30% of New Zealand’s land, along with less than 1% of the country’s marine environment, for conservation and recreational purposes.

The last few decades saw the formation of numerous grassroots organisations that focus on their specific regions or even on just one endangered species. Registered as non-profit trusts, they are run by and rely on work done by volunteers with a passion for the environment. Examples of such organisations include NZ Native Forest Restoration Trust, Next Foundation, New Zealand Whale and Dolphin Trust, Mackenzie Basin Wilding Tree Trust, Kea Conservation Trust, and Yellow-eyed Penguin Trust, to name just a few. They range from large country-wide organisations, to small community groups with a handful of enthusiastic locals. One such group is the Pomona Island Trust.

In 2005, Manapouri residents Lance Shaw, wife Ruth and brother Hunter, came up with the idea of making two islands on Lake Manapouri, Pomona (Pōhuruhuru) and Rona (Puhiruru), predator-free. They formed the Pomona Island Trust co-opting other dedicated conservationists with Prof. Alan Mark of Dunedin as a patron, and Te Anau farmer John Whitehead (who became the chairman of the trust, a post he’s still holding today).

Working under a Management Agreement with DOC, in 2006, the trust put in place a track and trap network targeting stoats. In 2007, a combined aerial and ground operation eradicated deer, possum, rats, and mice. According to Whitehead, hired contractors removed five deer and 400 plus possums from Pomona, while Rona had only mice and stoats present prior to eradication. For several years, regular checks of the traps by volunteers found no mammalian pests and the islands were declared predator-free. With no pests, the two islands became potential safe havens for endangered species.

“In 2009, eighty South Island robins were translocated to Pomona and Rona from other parts of Fiordland National Park. Those on Rona all flew off the island, but the Pomona population grew from strength to strength,” the trust chairman says.

At 262 hectares, Pomona Island is the largest island in Lake Manapouri and is the largest inland island in New Zealand. Rising 340m above Lake Manapouri, sporting some impressive bluffs, the island is 500m from the mainland, separated by the aptly named Hurricane Passage. It’s almost completely bush-clad with mixed beech-kamahi, rata, and podocarp forest. In years gone by, introduced predators and browsing animals had a severe impact on the island’s biodiversity, particularly on native birds.

Rona Island is the second largest island in Lake Manapouri, although at 60 hectares it is only a quarter the size of Pomona Island. However, the vegetation and birdlife on Rona was in much better condition than that on near-by Pomona. With only stoats and mice present on the island, the damage to its biodiversity has been significantly lower. So much so, that DOC Haast started using Rona as a creche for juvenile Haast tokoeka (kiwi), moving them to the island for six months before bringing them back to Haast Kiwi Sanctuary when, at 1.6kg body weight, they became big enough to fend for themselves. Since then, over 100 birds have found temporary refuge there.

In 2010, DOC released 19 kiwi on Pomona Island, hoping they would breed. And they did.

“They were laying eggs. We have lots of cameras on the island and we see young kiwi birds, so we know they are breeding. Trail cameras have really changed the way we work. We now see what’s going on,” Whitehead says.

The idea of translocations came from early days in conservation and was pioneered by Richard Henry in the 1890s. Today this is done when species numbers are low and isolated to one location, as is the case of the Haast kiwi.

Haast tokoeka (from “toko weka” literally meaning “a weka with a walking stick”), a shy, mountain-loving bird, is one of New Zealand’s rarest kiwi. Only about 450 of them are left with more than half of the known population living in the 11,000-hectare Haast Kiwi Sanctuary, where the battle continues to save these birds from extinction.

Apart from the original Haast population of tokoeka there are now three more wild populations on Coal Island, Pomona Island and Orokonui Ecosanctuary. This spreads out the risk and gives more security that if something happens at one location, the whole population won’t be wiped out.

The statistics are stacked quite heavily against the kiwi. According to DOC, without predator control, 95% of kiwi chicks are killed before they reach reproductive age.

Volunteer Jo Marsh with the Haast tokoeka on Pomona Island.
Photo: Fay Edwards

Pomona Island Trust looks after both Pomona and Rona islands, working hard to maintain their pest-free status, so DOC can continue its kiwi programme. Sadly, the trustees must sometimes face disappointments: “In 2010, things were looking well, and DOC translocated 60 mohua (yellow head) to Pomona. They were doing well until 2019, when, following a beech mast (prolific flowering of beech trees), the population of rats skyrocketed and our mohua got whipped out. Because of the lockdown we weren’t allowed to go to the island. After the lockdown we caught about 156 rats in the traps,” Whitehead laments.

“We’ve got a network of about 200 traps and 180 bait stations on a 100m x 100m grid. It takes six people all day to check and re-bait all traps,” he says.

Pomona Island Trust Chairman, John Whitehead and volunteer, Beth Masser re-baiting a stoat trap.
Photo: Alina Suchanski

Our volunteer group splits into six teams, each allocated to a different trap line. Our job is to check and re-bait every trap on the island with fresh eggs, rabbit bait, and peanut butter.

I’m in a team of three with John (the trust chairman) and Beth (a volunteer, like myself). We have the easiest route that follows the shore of the island, yet at times it’s far from easy. We have to climb under or over fallen trees, bush-bash through scrub and scramble over bluffs. Every 100 metres we have to stop, unscrew the lid of the trap, remove the old bait, replace it with fresh, and record what we found in the trap. Luckily, our team only found three dead rats, as removing them from the trap is not a pleasant task.

A carpet of orchids in full bloom on Pomona Island is a sign that there are no deer or possums present.
Photo: Alina Suchanski

Despite that, the walk through the bush is a treat. The whole understory benefits from the absence of browsers, such as deer and possums. The plant biodiversity is much greater than on the mainland and I have never seen so many orchids anywhere else in New Zealand native forest.

In the afternoon, the teams reconvene on a beach waiting for the water taxi to pick us up. Overall, we collected 26 rats on this trip, a sign that there are still too many rodents on the island.

The work of the Pomona Island Trust has been acknowledged by both local and national government. In 2011, the trust was the recipient of the Green Ribbon Award, which is the Ministry of the Environment’s supreme award, and in 2016, they received the Southland Community Environment Award from Environment Southland. This is well deserved for a community-based trust run entirely by volunteers.

“We’ve had over 1000 volunteers since the beginning. Sometimes we take school kids out there. You get a kid to hold a kiwi and you have a conservationist for life,” Whitehead says.

Sources: 1. The Penguin History of New Zealand, Penguin Books 2. A little Pomona History, Pomona Island Trust

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