5 Dec 2017
Stars of the Red List: two kiwi species are no longer Endangered
Not one, but two of New Zealand’s kiwi species are in recovery thanks to nearly 30 years of egg rearing, predator control, and community devotion.
By Kevin Hackwell, Chief Conservation Advisor – Forest & Bird
Whoever said dinosaurs are extinct has never seen a kiwi. As dusk approaches, you can hear their calls echoing from New Zealand’s native forest. As you venture in, you spot their large, three-pronged footprints imprinted in the earth. And there’s nothing to prepare you for the sight of this unique flightless bird. Eyewitnesses have said that the only real way to describe a kiwi is like a vestige from the Jurassic era: big and heavy, it moves in a completely unique way, swaying its hindquarters to power its thick, strong legs. It’s a surreal sight.
But unlike its dinosaurian ancestors, it doesn’t look like the kiwi needs to fear extinction any time soon. Thanks to nearly 30 years of dedication from government bodies, local conservation groups and the Maori community, two species of kiwi have become the stars of the 2017 Red List: Rowi Apteryx rowi and Northern Brown Kiwi A. mantelli have just been downlisted from Endangered to Vulnerable.
It’s a true underdog success story: the Rowi (also known as Okarito Kiwi) has increased from a mere 160 individuals in 1995 to 400-450 adults today. And in some areas the Northern Brown Kiwi’s populations are estimated to be growing by over 2% a year.
The reason for their decline was an age-old one: invasive species. In this case, stoats, ferrets and feral cats preying upon the eggs and chicks. And even the adult birds weren’t safe, with many Northern Brown Kiwis falling prey to wandering dogs – often the beloved pets of ever-spreading human populations at the top of New Zealand’s North Island.
Something needed to be done. And so, in 1991, the Department of Conservation joined forces with the Bank of New Zealand and Forest & Bird (BirdLife in New Zealand) to create the National Kiwi Recovery Program. They knew that the best way to achieve something great is to break it into clearly-defined, manageable stages: these became the Kiwi Recovery Plans.
The first Kiwi Recovery Plan involved gathering information: how many kiwis were left, where were they living, and what comprised their biggest threat. Nest predation, especially by stoats, was found to be the main cause of decline. Following lobbying by Forest & Bird, five large kiwi sanctuaries were established in the wild, with a commitment of NZ$ 2 million a year for research into how best to manage the kiwi and control the impacts of predators.
But while they were busy researching methods of stoat control, faster action needed to be taken to increase juvenile survival. And so, Operation Nest Egg was born.
Kiwis lay the largest egg in relation to their body size of any bird species: up to a whopping 20% of the female’s body. Operation Nest Egg ensured that this huge amount of energy didn’t go to waste. The project removed kiwi eggs from the wild, hatched chicks in captivity and then raised them either in captivity or in a predator-free crèche. Once they reached a stoat-safe weight of around one kilogram, they were released back into the wild. And it worked – the technique was found to increase juvenile survival from a heartbreaking 5% to an encouraging 60%.
Using the knowledge and tools developed in the kiwi sanctuaries, the third Kiwi Recovery Plan focused upon rolling out pest control on a landscape scale. It achieved this through empowering communities to get involved in managing their own kiwi populations, which led to a proliferation of community-led projects throughout New Zealand. The emphasis was on managing the birds as part of a healthy, functioning ecosystem, where kiwi acted as an indicator of the health of the habitat as a whole. By helping the kiwi, the community would also benefit a suite of other native flora and fauna.
In some cases, the focus continued to be on Operation Nest Egg. Other groups created ‘kōhanga kiwi’ sites, where kiwi populations are built up in locations where predators are absent or scarce (for example islands, or behind predator-proof fences). Offspring are then translocated to create new populations on the mainland, or to supplement existing wild populations.
Since the publication of the third Recovery Plan, significant advances have been made in the understanding of how best to control introduced predators to protect kiwi, especially in the North Island. Work at the kiwi sanctuaries has improved the ability to protect kiwi in situ over large areas, including through the use of aerial toxins to control stoats.
A better understanding has also been developed of the limitations of ground-based pest control. When using either traps or toxin baits, a particularly important discovery was the need to occasionally introduce a phase of the other technique to target those stoats that had become either trap – or bait – ‘shy’.
The ability to reduce the threat of dogs has remained a significant challenge to kiwi recovery, especially for kiwi populations that are located in close proximity to humans. Whether they are pets, working dogs, hunting dogs or feral, they can all kill adult kiwi.
In Northland, it has been shown that the average lifespan of an adult brown kiwi is only 13–14 years, compared to the 30–40 years of all other brown kiwi populations. This is mainly due to predation by dogs. And as a long-lived species with low reproductive rates, the loss of adult kiwi from a population – cut off in its reproductive prime – far outweighs the impacts of predation on juveniles.
Where dogs are an issue, even a single dog can easily turn the tide for a local population and can quickly undo years of conservation work.
Despite the considerable successes of the third Recovery Plan, unmanaged populations on the mainland continue to decline by around 2% a year. This was recognised by the Government in 2015, with a commitment for extra funding to turn the 2% decline into a 2% gain per year across all five of New Zealand’s kiwi species.
The fourth Kiwi Recovery Plan (2017–2027) is now awaiting publication and will set the ambitious goal of building kiwi populations from 70,000 to 100,000 by 2030.
To achieve this target, the Plan proposes to roll out predator control over even larger areas, with greater cost-effectiveness than ever before. Landscape-scale predator control will be taken to a new level, particularly for species in the South Island, where kiwi populations are often dispersed across vast areas of rugged terrain, and only a small proportion of kiwi currently receive any form of management.
The Plan also proposes to expand kiwi management on the back of the government’s proposal to make all of New Zealand predator-free by 2050. Since New Zealand pioneered the technology in the early 1960s, invasive species eradication operations have grown at an exponential rate. Because of the significant growth of knowledge around pest control over the past decade – much of it coming out of kiwi recovery research – it is predicted that this exponential trend will continue.
The Predator-Free initiative has nationwide support and has been enthusiastically adopted by community conservation groups, local Maori communities, philanthropists and everyday New Zealanders.
In both scale and breadth, kiwi recovery is one of the most unique and successful conservation partnerships in New Zealand. The Kiwi Recovery Group has expanded from only three original members to include Maori, captive management practitioners, independent researchers and community representatives. It doesn’t just create the Recovery Plans: it also provides regular expert advice to the Department of Conservation and field conservationists on how to put them into action.
Work stretches from the top of Northland to Stewart Island (Rakiura) in the south, with active participation from hundreds of diverse stakeholders. And it benefits all five kiwi species, so when the next Red List is published, there is every chance that the threat status of other kiwi species will enjoy a positive upgrade.
This beloved and iconic bird has been the catalyst for advances in technology and habitat recovery that have benefited the whole of New Zealand’s ecology. It’s time for New Zealand’s honorary dinosaur to look towards the future.