As Cyclone Gabrielle bore down on Aotea Great Barrier Island, off-grid residents checked on neighbours and moorings, tramping huts and tracks were closed, and its rugged shores sheltered the Gulf from the worst of the storm.
The battle to safeguard the island’s wildlife and ecosystems has been a challenging oneand this month the Aotea Great Barrier Environmental Trust celebrated 20 years with the release of a new – and cautionary – report on the Birds of Aotea.
Tim Higham considers its legacy.
On a good day, visitors to Aotea Great Barrier Island delight in seeing kākā in the pōhutukawa fringing its bays, scurrying moho-pererū or banded rail alongside its winding roads and pāteke in the lagoons and creeks that spill on to its long, sandy beaches.
But the island’s conservation gains have been hard won and much is still at stake.
“There’s nothing of conservation significance that’s happened on the island since 2002 that we haven’t covered,” says current Aotea Great Barrier Environmental Trust chairperson Kate Waterhouse.
The trust’s Environmental News has laid out the case for marine reserves, world heritage and conservation park status, the eradication of rats from nearby Rakitū Island in 2018, and getting Glenfern Sanctuary (established by trustee Tony Bouzaid) into public ownership. It has reported on the removal of wild goats and deer, rallied against mining and marine dumping proposals, published a major State of the Environment Report, championed the need for better protection of the island’s unique fauna and flora, and celebrated the efforts of a growing number of conservation initiatives.
But Waterhouse believes the island misses out because of the way the Department of Conservation ranks sites by individual species and ecosystem types.“Aotea has a richness of habitats – from maunga to moana – that should make it a national, even international, priority for investment.”
A 2019 study included Great Barrier in a list of 169 islands out of around 465,000 worldwide where mammalian pest eradication could be initiated in the next decade and would improve the survival of 9.4 per cent of the world’s most threatened birds, mammals, reptiles, and amphibians.
Possums, stoats, and other mustelids are not present on Aotea, yet around 80,000 birds are being killed annually by an estimated 1000 feral cats and a quarter of a million rats in its forests, according to the trust.
Eleven bird species have been lost since naturalist Frederick Hutton compiled the first list in 1867, including the forest birds kōkako, hihi/stitchbird, pōpokotea/whitehead and tīeke/saddleback. The last two kōkako on the island were transferred to predator-free Hauturu/Little Barrier in 1994 with the hope their offspring could one day return.
Founding chairman John Ogden says when the trust was formed, he expected there wouldn’t be a rat left on the island in 20 years. “It was so bleedingly obvious, the difference this would make to the birdlife and the forest.”
The retired associate professor admits now he is an ecologist not a social scientist, and finding a path to share the trust’s vision of a rat and feral cat-free island has been a bumpy road at times.
On the trust’s 10th anniversary, Ogden co-authored a paper for an international scientific journal with fellow founding trustee Judy Gilbert, titled Running the Gauntlet, noting the island’s independent-minded community had reservations about the use of aerial toxins and government agendas.
Gilbert has managed Windy Hill sanctuary for 23 years, creating employment to remove more than 60,000 rats and 400 feral cats, from an area that now covers 800ha of private land with 18 owners. Her efforts were recognised with a Queen’s Service Medal in 2017.
Rigorous monitoring has proven tūī, kererū and kākā, reptiles like the rare niho taniwha or chevron skink, and wētā, thrive in the absence of introduced predators, and fruit-bearing trees like taraire, pūriri and kohekohe can establish as part of forest succession.
In 2004, 2009 and 2012 locally extinct toutouwai or North Island robins were reintroduced to Windy Hill and Glenfern Sanctuary, and birds from both have establish a breeding population on Hirakimatā, the island’s highest peak. But high rat numbers elsewhere on the island have prevented other translocations, as well as natural recolonisation by birds like korimako/bellbirds, and smaller shearwaters and petrels.
The trust’s new Birds of Aotea report, authored by Ogden, says the toutouwai, titipounamu/rifleman, miromiro/tomtit, kākāriki/red-crowned parakeet in the cloud forest around Hirakimatā remain threatened. So too are populations of pārera/grey duck, matuku-hūrepo/Australasian bittern, pūweto/spotless crake, moho pererū and mātātā/fernbird, which occupy the large intact wetlands at Whangapoua and Kaitoke. Of particular concern is the pāteke with the island population of this once widespread native duck dropping from 1200 birds in 1996 to 400 in 2021.
Aotea is home to the largest population of tākoketai/black petrels, otherwise restricted to Hauturu, and small relict populations of tītī/Cook’s petrel, ōi/grey-faced petrel, pakahā/fluttering shearwater and kuaka/common diving petrel. The wider gulf has the greatest diversity of seabirds in the world with 27 breeding species, and if rats and feral cats were removed Aotea could become a significant island ark for seabirds, which only will be under added stress as the warming climate pushes food sources further offshore.
Waterhouse says, “The trust’s purpose has remained the same over two decades but the context has completely changed. The focus is no longer on the how, but the why and the who.”
Opo Ngawaka’s family are the sole residents of Māhuki, one of the Broken Islands on Aotea’s western coast, Māori land and home to the largest colony of takapū/gannets in the Hauraki Gulf.
Ngawaka is keen to see the return of abundance to the island’s forests and seas and views the decline in taonga species as part of the process of colonisation. “They are part of the story of loss that Ngāti Rehua Ngātiwai ki Aotea has suffered, of land, language, knowledge, and mana.”
He chairs the steering committee for the Tū Mai Taonga Project, now led by Ngāti Rehua Ngātiwai ki Aotea, with significant new funding from the Department of Conservation and Predator Free 2050 Limited through the Jobs for Nature programme, and from Auckland Council.
The project is building a conservation workforce in the north, where marae at Kawa and Motairehe are sited, and tapping into new knowledge and ways of working as a pathway to making the island predator-free.
It’s one of many projects the trust has either established or helped to get going.
Others include the Aotea Trap Library, which has loaned out more than 3000 traps in a community of 435 households; the Ōruawharo Medland Ecovision group, which hosts weekly volunteer days and is looking to expand its efforts beyond the popular surf beach and adjacent dunes and wetlands to join up with Windy Hill; and the annual Aotea Bird Count, often backed by grants from the Aotea Local Board, Auckland Council, Lotteries Commission, Foundation North and DoC.
Waterhouse is optimistic that in another 20 years, residents and visitors will be living among Aotea’s resurgent wildlife, underpinned by strong connections with nature in schools and kura, and by bylaws that the safeguard the community’s hard-won gains.
“I’d like to think we will hear kōkako again and the calls of many seabirds overhead at night, see the flashes of pink and blue shoals of maomao in the sea and the mushrooming headings of rātā, rimu and kauri in the forest, and perhaps some of the aunties will be saying, ‘Yes, we are back to the old ways.’”
In the wake of Cyclone Gabrielle all DoC tracks, facilities and accommodation were closed until February 20, pending assessment. See www.greatbarrier.co.nz and www.gbiet.org for updates and information.
Tim Higham is the author of Island Notes: Finding my Place on Aotea Great Barrier Island (The Cuba Press).