Successful recovery of North Island kokako Callaeas cinerea wilsoni populations, by adaptive management

摘要: Kokako Callaeas cinerea wilsoni (Callaeidae) populations are declining in unmanaged primary forests of the North Island, New Zealand. An 8-year experiment to determine cause decline was undertaken by controlling introduced browsing and predatory mammal pests two forest areas, then monitoring pest abundance, kokako chick output adult density managed an non-treatment block. Treatments were switched between one areas after 3–4 years. Reduction pests, especially brushtail possums Trichosurus vulpecula ship rats Rattus rattus, very low levels resulted significant increases all three study populations. This due primarily increased success nesting attempts, which number pairs attempting breed, initially as newly recruited young females formed with residual single males. The `adaptive management' approach using routine large-scale control a co-ordinated directly test pest-limitation hypothesis enabled researchers managers investigate increase simultaneously. Predation is more immediate current declines than competition. Management recover vulnerable should aim reduce (<1% trap catch for possums; <1% tracking rate rats, particular indexing techniques) at onset season, several consecutive