Reintroducing juvenile kaka to Mount Bruce Reserve : a thesis presented in partial fulfillment of the requirements for the degree of Master of Science at Massey University

Abstract

I investigated whether the release of juvenile Kaka (Nestor meridionalis) is an effective tool in the restoration of Kaka to mainland ecosystems. Five wild-caught juvenile Kaka and four hand-reared captive-bred juvenile Kaka were released at Mount Bruce Reserve in the North Island in June 1996. I assessed the suitability of each group for release by monitoring the survival rates, dispersal from the release site, and behaviour of the Kaka after release. The Kaka were released using a soft-release method. The four captive-bred Kaka were reared in aviaries at the National Wildlife Centre (NWC) at Mount Bruce prior to release. The five wild-caught Kaka were captured on Kapiti Island in May 1996 then transferred to the NWC. The Kaka were held together in aviaries at the NWC for two weeks, then released on 4 June 1996. Post-release the Kaka were provided with supplementary food at feedstations set up at the release site. Each Kaka was fitted with a transmitter and was individually recognizable by colour leg-band combinations. I monitored the Kaka on a daily basis for six months after release. Survival rates for both captive-bred and wild-caught Kaka were high after release, with 8/9 Kaka alive at 30 November 1996. Radio-contact with one of the wild-caught Kaka was lost in September. There was high site-fidelity after release, with most of the Kaka moving a limited distance from the release site and generally staying within Mount Bruce Reserve. One wild-caught Kaka was located at Hokio Beach on the west-coast of the North Island in June 1996. This bird was captured and returned to the NWC. After being re-released at Mount Bruce Reserve in August 1996 this bird has remained within the Reserve. The Kaka adapted well to the new environment of Mount Bruce Reserve, locating and feeding on a variety of natural foods, and interacting with each other after release. All four captive-bred Kaka and three wild-caught Kaka regularly fed at the supplementary fcedstations after release. These results suggest that it is possible to reintroduce Kaka to a mainland site. Translocated wild-caught juvenile Kaka will stay near the release site after release when released using a delayed-release method. Juvenile wild-caught Kaka and juvenile captive-bred Kaka can survive on the mainland in the presence of predators, when assisted by post-release supplementary feeding and low-level predator control.