Hundreds of New Zealand's largest giant weta will be released on pest-free islands in the Hauraki Gulf after a successful breeding programme at the Auckland Zoo.
The first 150 weta punga will be released on Motuora Island today, with another 150 to be released on Tiritiri Matangi next month. Two hundred more will be released in the wild this year.
The weta are considered nationally endangered and are one of the world's heaviest insects, weighing as much as a sparrow.
All the weta are the offspring of six males and six females moved to the zoo in May 2012 from Little Barrier Island, the only place they are now naturally found, as part of the Department of Conservation's (DOC) breeding recovery programme.
The zoo's curator of ectotherms and birds, Richard Gibson, said new techniques involving rearing the insects in groups as well as individually were trialled within the zoo's temperature-controlled weta facility.
"Because we were hatching so many, we established groups of anywhere from five up to 100 animals in different-sized enclosures," he said.
"Within these we also created 'wetapunga apartment blocks' from bamboo and hosepipe to give individuals the necessary hiding places.
"In addition, we had to ensure adequate height and hanging places for the weta to moult successfully, which they do 10 times to reach adulthood."
DOC scientific adviser Chris Green said the aim was to establish several weta populations around the gulf, ensuring the survival of the species and their long-term security.
"By using captive breeding we can now transfer several pioneer populations to other islands, improving the chances of the species surviving in the event of a catastrophe on Little Barrier wiping them out for ever," Green said.
- Fairfax Media