Eight of the rarest type of kiwi have died from a respiratory tract infection at Wellington Zoo.
The young rowi, who had been living on predator-free Motuara Island in the Marlborough Sounds, were being treated for a type of worm at the zoo when they started showing signs of respiratory problems, thought to be caused by the bark they were being housed on.
DOC's Franz Josef biodiversity manager Jo Macpherson said the bark was regularly used by the zoo with no adverse effects, and the birds' weakened immunity had made them more susceptible to the illness.
The respiratory tract infection was caused by a fungus called Aspergillus spp which is common to the natural environment but can cause severe damage to the lungs and air sacs in birds.
''This is an extremely rare and unfortunate occurrence and has come as a great blow,'' she said.
Ms Macpherson said it a difficult disease to treat and the zoo and DOC staff are devastated by the loss.
''It is also a tragic loss for Kiwis for kiwi, who have supported the rowi programme and have been an integral player in the return of 200 rowi back to the wild.''
With fewer than 400 of the birds remaining, DOC has been working to bring rowi back from the brink using BNZ Operation Nest Egg.
Unmanaged, a tiny proportion of rowi survive to adulthood - around 95 per cent are killed by stoats.
''These birds were removed from the wild as eggs in order to protect them while they grew big enough to defend themselves,'' said Ms Macpherson.
The kiwi had been transferred from the Marlborough Sounds to the zoo last month for specialist treatment.
Veterinary science manager Lisa Argilla at the zoo said after the first kiwi died on September 11, after which the remaining kiwi were removed from the enclosure.
Despite treatment for the respiratory infection, another seven kiwi died over the month.
''It was one of those races against time, we needed the birds to hold on a little bit longer for the drugs to do their work... but everything was against them once they got the disease, it's notoriously difficult to treat especially when they're stressed.''
Wellington Zoo chief executive Karen Fifield said she was satisfied staff had acted quickly once they saw signs of respiratory infection.
''These were animals in some way were compromised when they came.... their stress levels are different, things affect them more than it would a healthy animal.
''It's not excusing what happened and weasel out of it but you do have to take even more precaution when dealing with animals like this.''
Ms Fifield said the bark the birds were being housed on was old, weathered bark so it was unusual for it to contain the spores which are thought to have caused the infection.
The zoo would now be working with DOC on the protocol for working with endangered animals to assess how deaths like these could be prevented in the future. , including looking at whether or not it would continue to use the bark.
A further, unrelated kiwi death occurred at Massey University, for which the department is awaiting autopsy results.
- © Fairfax NZ News
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