Management Action-Restoration

Native birds and animals of New Zealand had very few predators. Until the introduction of pests and rats onto New Zealand soils, they were able to roam freely and could be found in great numbers. Nowadays, they are subjected to extinction at an alarming rate. In response, the Department of Conservation sent out a team to eradicate rats through an experiment that proved successful. It was planned that in 1990, the Department of Conservation were to introduce some of the endangered animal species back onto Breaksea Island.

Invasive alien mammals are the major driver of biodiversity loss and ecosystem degradation on islands. Over the past three decades, invasive mammal eradication from islands has become one of society's most powerful tools for preventing extinction of insular endemics and restoring insular ecosystems. As practitioners tackle larger islands for restoration, three factors will heavily influence success and outcomes: the degree of local support, the ability to mitigate for non-target impacts, and the ability to eradicate non-native species more cost-effectively.

Background: Recent reports on the state of the global environment provide evidence that humankind is inflicting great damage to the very ecosystems that support human livelihoods. The reports further predict that ecosystems will take centuries to recover from damages if they recover at all. Accordingly, there is despair that we are passing on a legacy of irreparable damage to future generations which is entirely inconsistent with principles of sustainability.

New Zealand’s offshore and outlying islands have long been a focus of conservation biology as sites of local endemism and as last refuges for many species. During the c. 730 years since New Zealand has been settled by people, mammalian predators have invaded many islands and caused local and global extinctions. New Zealand has led international efforts in island restoration. By the late 1980s, translocations of threatened birds to predator-free islands were well under way to safeguard against extinction.

Seabirds are notoriously sensitive to introduced mammalian predators and eradication programs have benefitted seabird populations and their habitats on numerous islands throughout the world. However, less evidence is available from the tropics as to the benefits of rat eradication. Here, we report the seabird recovery and vegetation dynamics on a small coralline island of the tropical western Indian Ocean, eight years after Norway rat (Rattus norvegicus) eradication.

A study tour of restoration projects was conducted for seven participants from four Polynesian countries (American Samoa, Niue, Samoa and Tonga) between March 20 and 27, 2015 to Auckland, New Zealand. All participants are involved in restoration projects in their home country, most funded under the GEF-PAS "Prevention, control and management of invasive alien species in the Pacific Islands" Project. Seven restoration sites were visited, including 3 island sites and 4 mainland sites.