Pests or Treasures

Forest and Bird, Issue 307, 1 February 2003, Page 3

Pests or Treasures

Hauturu (Little Barrier Island) was New Zealand’s first nature reserve and a jewel in the conservation crown, but it cannot achieve its full potential as a treasure house of biodiversity until it is free of all alien mammals. Following the eradication of feral cats from Hauturu in 1980, recovery of some native birdlife occurred, and translocation of kokako and saddleback to the island was made possible. Further recovery of native ecosystems and wildlife is inhibited by the continued presence of kiore, which are now the only alien mammal remaining. The rats limit the recovery of vulnerable wildlife such as burrowing seabirds, tuatara, lizards and giant weta, and they inhibit the regeneration of native trees and rare plants such as the woodrose, whose flowers are browsed by kiore. Complete eradication of kiore from Hauturu is the only way to ensure that biodiversity recovery can proceed unhindered. There have been great benefits of eradicating this and other invasive rats from many islands around the world. Localised control, harvesting or any approach that involved the retention of any kiore on Hauturu would pose an unacceptable risk of continued ecological damage, given the propensity of rats to disperse and increase rapidly in numbers. The sooner that kiore are eradicated from Hauturu, the better. Only when that is done can this superb island reserve recover its full potential as a haven for native biodiversity. — MICK CLOUT Chair, IUCN Invasive Species Specialist Group. Ngati Wai, who maintain mana whenua over the island, regard kiore as a tribal treasure.