Kakapo comeback?

Forest and Bird, Volume 23, Issue 2, 1 May 1992, Page 2

Kakapo comeback?

THIS LAST ‘YEAR. has been one of mixed success in the fight to save the world’s largest parrot from extinction. Six chicks hatched recently on Codfish Island but only three have survived. Just over 50 kakapo are believed to exist and fewer than 16 of them are female. Their high vulnerability to introduced predators and competitors, coupled with a remarkably low natural reproductive rate have been the cause of the bird’s decline. No natural population remains and virtually all re-

maining birds have, in the past decade, been relocated on Little Barrier, Maud or Codfish Islands. The $2-million six-year kakapo recovery programme began in 1989 as a partnership between the Department of Conservation and Forest and Bird, with funding from aluminium maker Comalco. Last summer male kakapo on all three islands (all reserves managed by DoC) attained breeding condition and "boomed" intensely. On Codfish Island near Stewart Island, more than 20 bowl systems (male booming and courtship sites) were developed and used by the birds, indicating that most, if not all, of the 20 males released there since 1987 had survived and were in breeding condition. Booming, a characteristic male courtship display, was intense each night from late January until mid-March. This was the first sustained booming on Codfish since the birds were released there. The booming and associated courtship displays were not in vain. At least 11 eggs were laid in four nests and six

chicks hatched in March and April — the first known to hatch on the island and the first to hatch without supplementary feeding since the recovery programme began. Codfish is also occupied, however, by the kiore, or introduced Polynesian rat. Within a few days two kakapo chicks and two eggs were taken by kiore. The three remaining chicks were undernourished due to the failure of podocarp fruiting on the island and competition from kiore for food. The two weaker chicks have been taken for hand rearing to Auckland Zoo, and DoC is now reassessing its hands-off management practice on Codfish and the long-term problem of kiore. On Little Barrier, at least ten of the 13 males and four

of the nine females placed there in 1982 survive. Since no breeding was apparent by 1989 the supplementaryfeeding of some females began. The technique brought immediate results — at least two females attempted to breed in early 1990 although no young survived. The following season (1991) four females nested, eight eggs were laid and two young survived. Not only were these the first to have been raised on Little Barrier, but

they were the first young known to survive anywhere since 1981 (see cover of Forest & Bird May 1991). Thus, supplementing the diets of free-ranging kakapo on Little Barrier has not only been effective in inducing breeding, but also in enhancing the frequency of breeding — a crucial factor in a species that might otherwise breed only at intervals of 4-5 years or more. On Maud Island in Pelorus Sound where all five kakapo are being given supplementary food, the males boomed intensively for four months. However, although they interacted with the two females, no breeding took place. Unfortunately stoats, a serious predator of kakapo eggs and young, have again reached Maud — having

swum from the mainland some 900 m away — and are proving difficult to eradicate. Although they are not considered a major threat to adult kakapo, DoC proposes relocating at least some of the Maud Island birds on Mana Island off the Wellington coast. One male is to be placed on Mana this month to test the island’s suitability. Mana has recently been declared rodent-free after a successful mice-eradication campaign (see last issue of

Forest & Bird). If Mana proves suitable for kakapo then other birds from Maud may be relocated there later this winter, but Maud will remain the centre for captive management of the species. Don Merton, co-ordinator of DoC’s kakapo recovery programme and long-time champion of the species is happy with recent progress. He believes that recent advances in our knowledge and understanding of the kakapo, as well as in our ability to

manage it amount to a major breakthrough. He is confident that averting extinction and bringing about recovery of this remarkable bird are now realistic and attainable goals. A happy footnote: Don Merton was granted an honorary Doctor of Science degree by Massey University earlier this month in recognition of his contribution to endangered species management both within New Zealand and internationally.