South Westland kiwi deaths a puzzle


The Department of Conservation has begun the mass vaccination of Haast and Okarito kiwi chicks after seven young birds — some of the rarest kiwis in the country — died suddenly on a predator-free island in Lake Manapouri.
All remaining kiwi have since been evacuated from the island.
The deaths come only six months after eight Okarito kiwi died at Wellington Zoo from respiratory tract infections.
DOC said yesterday seven young Haast kiwi had died on Rona Island, in Lake Manapouri. Ten chicks were transferred to the island in January and February.
Over the past weeks, seven birds have been found dead and pathology results from Massey University have shown that for one bird an infection known as erysipelas was the probable cause of death.
Tests for erysipelas came back negative for the six others, with parasites and emaciation the probable cause of death. Despite extensive testing, it is not clear what killed the four others.
DOC vet Kate McInnes said the risk of erysipelas in birds was usually low.
Healthy birds appeared resilient, but it could prove fatal to young or stressed individuals.
DOC said it decided to take a precautionary approach using antibiotics and vaccinations, which were effective in treating and preventing erysipelas.
“Even though the bacterium has only been found in one bird, this is a preventable infection and we want to give every kiwi chick the best start in life. The occurrence of erysipelas appears restricted to Rona Island but we have decided to vaccinate all Haast tokoeka and rowi BNZ operation nest egg chicks as a precaution.”
Seventeen Haast tokoeka and 44 Okarito rowi have received the first of two vaccinations with the help of the West Coast Wildlife Centre and Pacific Vet Ltd in Christchurch.
The remaining two live chicks from Rona Island have been sent to Wellington Zoo for precautionary treatment and monitoring and are doing well. The 10th bird was unable to be located.
DOC senior ranger James Livingstone, of Franz Josef Glacier, said the deaths highlight the challenges in trying to protect young Haast tokoeka kiwi, but that overall the intensive management programme was benefiting the species.
“It’s always very disappointing to lose chicks and we will be considering new procedures such as preventive vaccination to limit the risk of erysipelas to our young birds in the future.”
“But overall this season we still have a 60% survival rate through the BNZ operation nest egg programme. Without active management this would be less than 5% due to predation in the wild.”
The department would assess Rona Island as a safe place for kiwi before birds were returned there, Mr Livingstone said.
The creche is run by the Pomona Island Charitable Trust work.