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Orokonui Ecosanctuary conservation manager Elton Smith reflects on the history and future of predator control in the context of our hopes for a predator-free New Zealand by 2050.

Predator-free New Zealand 2050 is the new and, maybe, last great battle in conservation. The goal is to be free from some of our mammalian pests, namely two species of rat, the possum and my own personal nemesis — the rather brilliant stoat.

Having helped look after the Orokonui sanctuary for the past 11 years, I have a reasonable idea just how difficult a predator-free New Zealand will be to achieve. If it can be a struggle to remain free of them  in a 307ha sanctuary, how on earth do you  extend the hunt to something like 27 million hectares?

As it currently stands, even with the most modern technology, predator-free New Zealand probably isn’t possible.  But when you consider just how much progress has been made in the past 30 years, I believe there is an excellent chance of success by the 2050 timeframe.

Orokonui’s roots can perhaps be traced back to 1988. The eradication of ship rats from the 170ha Breaksea Island in Fiordland National Park saw the first sizeable chunk of land to reclaim the title predator free. This operation was so successful that one of the most predator sensitive of species, the saddleback, could be released to flourish there. The ultimate recognition of its success came 25 years later when an Orokonui-led team was permitted to export 50 saddleback back to the mainland.

The progression of island eradications then got bigger and bigger: Kapiti Island (1965ha) in 1996, Little Barrier (3080ha) in 2004 and Rangitoto-Motutapu (4040ha) in 2009.

And, while predator control has been evolving, eradication on the mainland hasn’t been an achievable goal. Nevertheless, in the Department of Conservation’s ‘‘Mainland Islands’’, a suite of introduced pests (and not just the predators) could be controlled to low levels. For the first time since colonisation of the mainland, the decline of our native biodiversity was not only halted but reversed.

Then entered a powerful new conservation force: the community. With the establishment of Zealandia, in Wellington, the era of the fenced sanctuary — currently the gold standard for mainland ecological restoration — arrived. In the mid 2000s came "peak fence", when Orokonui (307ha), Rotokare (230ha) , Bushy Park (100ha) and the mother of all fences, Maungatautari (3400ha) were constructed. With fences you could now achieve multiple mammalian eradications and, in some cases, up to 13 species. This was the stuff of a wildlife manager’s dream.

As with any innovation it was the constant development of tools that helped advances in predator control. In the early 1990s, best-practice trapping was the Fenn trap, a true classic that has been used in Britain since the 1950s. These were displaced by the more humane Doc traps in the early 2000s and we have currently entered the age of the self-setting trap; the A24 and the like. Orokonui, with its host of predator sensitive species, has to keep up with these innovations and we tend to refine our systems every year. This year has seen the introduction of new rodent bait/trap stations, trap boxes and a new ferret juice lure. Yes, ferret juice.

In 30 years, predator control in New Zealand has come a long way; from eradicating ship rats on an 180ha island in Fiordland to 12 species of pests within a 3400ha fence in the Waikato, from English traps to ones that reset themselves. Some traps can now even send you a text message.

The culmination of this progress is the new goal of Predator-Free New Zealand 2050 and Dunedin is helping lead the charge. In March, the Predator-Free Dunedin initiative was launched with the support of 19 local organisations. Some of these, such as Orokonui, OSPRI, Doc and the Otago Peninsula Biodiversity Trust, are already well established as leaders in predator control. Success breeds success, and now further community projects, such as the Orokonui Halo and Valley Urban Ecosanctuary, are joining the cause.

It is this collaboration of many like-minded groups that will ultimately achieve the goal. Groups, of course, consist of individuals, so one way or the other we can all participate. Join an existing organisation or consider establishing some predator control in your own backyard and suburb. Happy trapping!

- Elton Smith has been Conservation Manager at Orokonui Ecosanctuary since its inception.