James and Thibaud Aronson post here their second report on ecological restoration in New Zealand, an island nation that seeks to eradicate non-native predators by 2050.
The government of New Zealand (or Aotearoa, as the Maori call it) has announced its goal to be predator-free by 2050, but the effort and expense required to eradicate the tens of millions of noxious animal and plant pests from the entire country is mind-boggling. One important development is technological in nature. Invasive mammal-killing traps are not very costly, but they do require regular maintenance. Some companies, such as this one, are designing and manufacturing automatic traps that humanely kill pest animals and then reset themselves.
There are still many obstacles to achieving a predator-free New Zealand, but the situation would be far worse today if not for impressive political will and public buy-in.
Much of the native fauna has only survived to this day because, in addition to the two main islands, New Zealand also possesses many small offshore islands, some of which were never reached by introduced pests, like rats and stouts. Eradication campaigns have for many years been carried out on various islands relatively near to shore, to make them ‘pest-free sanctuaries’, where small salvage populations of rare and endangered species have been translocated and established successfully. Several ‘mainland islands’ have also been established, on North Island and South Island, completely surrounded by massive pest-proof fences, with ongoing trapping and poisoning efforts to eliminate any predator that might manage to get in.
We visited Tawharanui, one such sanctuary in the north of the country. While it is in an area that still has some native forest, the contrast is remarkable as soon as one passes the fence. The first notable difference is an audible one. The birds of New Zealand are unusual in that they sing all day long, and they are loud. James Cook, the first European to set foot on the islands, described the birdsong as “deafening”. Today, most of the forests are quiet, and the few birds that can be heard are exotic species, introduced by nostalgic, home-sick Europeans. Tawharanui gives an idea of what things once were like. Within minutes, we were struck by the diversity and abundance of life, another world entirely compared with the unprotected and second growth forests. Half a dozen endemic species thrive here that can hardly be encountered anywhere else on the mainland, and all of them display the characteristic fearlessness that has caused their downfall.
A North Island robin (Petroica longipes), displaying the typical inquisitive behavior that has caused the extinction of so many insular birds worldwide.
A few days later, we took a boat to Tiritiri Matangi (“a place tossed by the wind” in Maori). This small island, an hour away from Auckland, is one of the country’s most famous wildlife sanctuaries, and a remarkable experiment in ecological restoration. It was intensively cultivated and pastured until 1971, when it passed back to government ownership, with the intention of making it a nature reserve. However, as natural regrowth was very slow, a massive volunteer program was launched in 1984, leading to the planting out of over 250,000 native trees in the next ten years. Under the guidance of Dr. John Craig, and colleagues, 25 years of work at Tiritiri Matangi has led to much restoration of both natural and social capital.
A key component was a large-scale pest eradication program applied with great thoroughness. Once the habitat was deemed suitable, several endangered species were translocated from other more isolated islands where they persisted, nearly all of which have since established successfully. The regenerating forest offers great opportunities to view the wildlife, and tens of thousands of people visit the island every year. The success of the project has since led to similar projects on other offshore islands in New Zealand.
The stitchbird (Notiomystis cincta), the sole representative of its family, was once common throughout New Zealand. Within a century of the Europeans’ arrival, only a few hundred birds persisted on a single offshore island. It has since been translocated to Tiritiri Matangi and several other pest-free islands.
New Zealand’s best tool in this struggle is probably its people. Great efforts have been made in communicating to children the uniqueness of their endangered species, and how essential is the eradication of the introduced pests, no matter how cute and cuddly they may be. This was true at Tiritiri Matangi, and everywhere else. See the two key references cited at the end.
A sign describing one of many community programs we saw, where locals carry out conservation work, such as this eradication program along the Kepler Track, near Te Anau, South Island.
Invasive exotic plants are also a serious obstacle to ecosystem recovery, especially various species of introduced conifers that have escaped commercial tree crop plantations and become naturalized and out-of-control on native grasslands little prepared for such an encroachment. But the use of native plants has really taken off, with sophisticated, and inspiring native plant nurseries found throughout the country, and everywhere from city gardens to public works projects, native plants being used more and more every year. As a result, native species, from green geckos to tuis, the country’s most famous songster, can now be seen right in the middle of Auckland.
A Tui (Prosthemadera novaeseelandiae) perched on a native Hebe shrub on Stewart Island.
Stewart Island, the country’s third largest island at 1750 km2, is an example of what the country as a whole could aspire to. Royal albatrosses come into the harbor following fishing boats, blue sun orchids bloom on the roadsides, and kiwis come out at night to forage on the rugby field.
Oban, the only settlement on Stewart island. Walk in any direction out of town, and you quickly find yourself entering the surrounding national park.
A blue sun orchid (Thelymitra venosa), blooming on a roadside embankment on Stewart Island.
Now, of course, only 400 people live permanently on the island, 85% of which is a National Park, and most people on the island depend on tourism for income. The model obviously cannot be translated directly to the country as a whole. All dogs on the island must receive kiwi-avoidance training, and when a pair of variable oystercatchers decided to nest on the field in the middle of the primary school’s playground, the area was cordoned off, and several signs put up, telling children what a privilege it was that their school had been chosen by the parental pair, and to keep well away from the nest. The chick hatched while we were there, and happily crossed over the road safely, with his parents following the reckless chick, to the nearby beach. There too, even though people (but not dogs) are present every day and evening, except when it’s pouring down rain, these birds are nearly guaranteed a watchful and caring stewardship on the part of the locals and quickly tuned-in visitors. These simple things show a will on the part of the local people to exist within the native ecosystem, rather than imagining themselves outside it, and licensed to do whatever they will, and to hell with the consequences. The rest of the world would do well to take a page from NZ’s book.
Newborn variable oystercatcher (Haematopus unicolor) on the beach, 50 meters from Oban’s main hotel.
Additional recommended reading
Craig J, Mitchell N, Walter W, Galbraith M, & Chalmers G. 1995. Involving people in the restoration of a degraded island: Tiritiri Matangi Island. In: Saunders DA, Craig JL, & Mattiske EM, editors. Nature Conservation 4: The role of networks. Chipping Norton, NSW, Australia, Surrey Beatty & Sons. Pp. 534–41.
Craig J, & Vesely E 2007. Restoring natural capital reconnects people to their natural heritage: Tiritiri Matangi Island, New Zealand. In: Aronson J, Milton SJ, & Blignaut JN, editors. Restoring natural capital: science, business, and practice. Washington DC, USA, Island Press. Pp. 103–111.
Natural History of Ecological Restoration 