Poor season for taiko

Forest and Bird, Issue 281, 1 August 1996, Page 6

Poor season for taiko

A BREEDING season that was looking like the best on record for New Zealand’s most be

endangered bird, turned out disastrously. Chatham Island taiko, which nest only in bush on the south-west of the main Chatham Island, had produced five or six eggs in January but by March all nests had failed and no chicks were raised. Once thought extinct, the taiko or magenta petrel, was rediscovered in 1978 when two of the burrow-nesting seabirds were caught by a team led by David Crockett. It was not until 1987, however, that a burrow —

the first seen in living memory — was found by a Department of Conservation/Crockett team, and measures could be put in place to protect the birds and their young in the burrows (see Forest & Bird May 1994). Although taiko numbers — thought to be between 45 and 150 — may be slightly higher than several other endangered birds, such as kakapo and fairy tern, the taiko’s situation is more precarious because of the combination of naturally slow breeding, the constant threat from a suite of introduced animals, the inaccessibility of their nesting sites for protection work, and the lack of techniques available to transfer them to a predator-free site. During the last nine breeding seasons, a maximum of three chicks have been successfully raised each year (although none of these chicks has been seen again). So when five or six active nests were found last season, hopes were high for a record production year. But by the end of February four chicks had gone missing and another possible nest was deserted. The remaining chick was killed in March. Predators were probably the key factor in these losses. DoC

staff believe that weka and/or rats caused at least three of the failures, and it is likely that they were also responsible for some of the others. Unfortunately a lack of close monitoring of the burrows by DoC means we cannot be certain. What is clear is that DoC needs to strengthen its efforts against the taiko’s predators. Virtually no rat control had been carried out around two of the burrows that failed in early February. Despite a major trapping and poisoning programme that has cleared thousands of weka, possums and rats and hundreds of cats from the general nesting area of the taiko, sign of these pests is still regularly found close to nesting burrows. Forest and Bird wrote to then Conservation Minister Denis Marshall in 1991 concerned that the control programme was not intensive enough and urging it be stepped up. The minister assured the society that DoC would continue to protect nesting birds and chicks from predators. Fortunately it appears that DoC will intensify its taiko protection efforts next season. In the past, the operation has

run on a shoe-string budget but the recent boost to DoC funding has allowed a full-time manager to be employed on the Chathams to specifically coordinate the taiko and the threatened parea (Chatham Island pigeon) conservation programmes. Seasonal workers will again be employed for predator control. Also coming up next season is a major DoC/Crockett programme using radio transmitters to find further nesting sites. Hopefully some chicks will survive to fledge next year and further nesting sites will have been found where these special but precariously surviving birds can be protected. Alan Tennyson Museum of New Zealand