Ecological restoration of islands in Breaksea Sound, Fiordland, New Zealand

New Zealand has long been renowned internationally for its innovative conservation strategies. Translocation as a conservation management technique was pioneered in Fiordland between 1894 and 1900 when Richard Henry undertook 700 transfers of a range of vulnerable birds such as kakapo (Strigops habroptilus) and kiwi (Apteryx australis) to Resolution Island (and smaller adjacent islands) from nearby mainland sites in Breaksea and Dusky Sounds. This far-sighted project was abandoned when introduced stoats reached the area. Biological surveys of islands in Breaksea Sound in the 1970s resulted in an ambitious island restoration project in which Norway rats (Rattus norvegicus) were eradicated from bush-clad Hawea Island (9 ha) in 1986 and rugged Breaksea Island (170 ha) in 1988. Before poisoning on Breaksea Island, South Island robins (Petroica australis) were transferred to Hawea Island as a precautionary measure. The resultant populations is the densest recorded, and they have even dispersed across 300 m of open water to neighbouring Wairaki Island (3 ha). South Island saddlebacks (Philesturmus carunculatus) were released onto Breaksea Island in 1992 with similar success and yellowheads (Mohoua ochrocephala) are confirmed breeding following an experimental transfer from the mainland in 1995. We undertook some of the first experimental translocations of lizards and invertebrates: Fiordland skinks (Oligosoma acrinasum) being released onto Hawea Island in 1988, and knobbled weevils (Hadramphus stilbocarpae) and flax weevils (Anagotus fairburnii) transferred to Breaksea Island in 1991. A programme to monitor ecological change, using several key, indicator species of flora and fauna, was set up before poisoning to document the benefits of eradication rodent pests.

Author Thomas, B. W.
Year 2002
Secondary title International Conference on Eradication of Island Invasives
Publisher Invasive Species Specialist Group IUCN
Pages 414-414
Control method Baiting
Region NZ