THE ROLE OF INTRODUCED PREDATORS AND COMPETITORS IN THE DECLINE OF KAKA (NESTOR MERIDIONALIS) POPULATIONS IN NEW-ZEALAND

We investigated the role of introduced predators and competitors in th e population decline of kaka, Nestor meridionalis, a previously abunda nt forest parrot endemic to New Zealand. We provided supplementary foo d to test if a shortage of high energy food was limiting breeding in k aka. However, because most nesting attempts suffered from predation an d we could not establish a non-treatment area, the role of competitors is still unclear. Kaka only bred in years when beech (Nothofagus) see ded. Over II years and 20 breeding attempts we recorded only four fled glings surviving to independence. Nine young kaka and four adult femal es were killed on the nest. We suggest that stoats were predominantly responsible for this predation. Kaka are relatively common on offshore islands without stoats, even in the presence of other predators and c ompetitors, bur are scarce an all islands containing stoats. We predic t that stoat predation will cause kaka to become extinct on mainland N ew Zealand unless stoats and/or kaka are managed. (C) 1998 Elsevier Sc ience Ltd.