In November 1948 the rediscovery of takahē, long thought to be extinct, caused great public interest. The New Zealand government quickly closed off a remote part of Fiordland National Park to prevent the bird from being disturbed.
There were differing ideas about how takahē should be protected. The official view of the Forest and Bird Society was that the birds should be left in peace to work out their destiny. But some were concerned that this would allow them to slip into extinction like the huia. A more interventionist strategy was to relocate the takahē to island sanctuaries and breed them in captivity. However, nothing happened for almost 10 years, partly because of lack of resources, and partly to avoid controversy.
Pūkaha Mt Bruce National Wildlife Centre
In 1957, visiting British ornithologist Peter Scott voiced his support for breeding endangered native birds in captivity while giving New Zealanders the opportunity to see them. An experiment to collect and incubate takahē eggs and rear the chicks led to the Pūkaha Mt Bruce National Wildlife Centre being set up in the Wairarapa. Initially, breeding takahē was only partly successful because knowledge of rare bird biology was limited. It took 20 years to develop successful breeding techniques, which were later applied to other bird species.
Ornithologist Don Merton commented: ‘The tragedy of Big South Cape was a timely and valuable lesson for us. It convinced even the most sceptical that predators could induce ecological collapse and extinctions. But it also has a massive, enduring impact because it shaped the way we developed policies about conservation and put them into practice.’ 1
Predators and extinction
Many biologists were reluctant to believe that introduced predators caused extinctions – following European experience, it was believed that predators were a normal part of the environment, and habitat destruction was the problem. This attitude changed in 1964, when rats gained a foothold on Big South Cape Island, near Stewart Island. The island had a large native bird population, including the only known South Island saddlebacks. Some saddlebacks were transferred to nearby rat-free islands, but the tiny Stead’s bush wren, the Stewart Island snipe, and the greater short-tailed bat became extinct. From then on it was accepted that human intervention was needed to save critically endangered species.
In the 1970s the protection of threatened species was led by the Wildlife Service of the Department of Internal Affairs, and since 1987 by the Department of Conservation. Their approach has been to:
- improve the birds’ natural habitat
- remove predators in areas where threatened species live naturally
- transfer threatened species to predator-free islands
- breed threatened species in captivity.
Numbers of takahē, kākāpō, black stilt and the Chatham Islands black robin – once facing extinction – have increased, as have kākā and kōkako numbers.
When National Radio announcer Robert Taylor began greeting listeners with a mimicked morepork call, the Wildlife Service provided him with a selection of bird-call tapes. When he moved to the early-morning programme in 1974, he took the bird calls with him. They became so popular that attempts to remove or modify them met with public outcry.
Small predatory mammals have been removed from some island sanctuaries. For example, rats and possums have gone from Kāpiti Island, and cats and rats from Little Barrier Island (Hauturu). A number of ‘mainland islands’ have been created by controlling predators and using fences. An example is Zealandia in Wellington.
Concentrated conservation efforts are costly. When a few threatened species are prioritised, there are fewer resources for other species.