Relocated kokako not found
Hopes of hearing kokako birdsong in Fiordland have been dashed with a recent survey finding no trace of a population established on Secretary Island three years ago.
The Department of Conservation, in partnership with the Fiordland Lobster Company, funded the transfer of 27 North Island kokako to Secretary Island during 2008 and 2009 to try to re-establish kokako in Fiordland.
In 2011 hopes of success were raised when two kokako pairs and a fully fledged juvenile were observed.
However, DOC biodiversity programme manager Lindsay Wilson said a survey of the island in March found no sign of the breeding pairs or any other kokako.
DOC ranger Megan Willans, part of the search team, said while the department could not be sure there are no surviving kokako on Secretary Island, evidence suggested most of the birds had perished.
Stoats were the only introduced predator on Secretary Island and a spike in stoat numbers was the most probable cause of the loss of the kokako.
Since the kokako were translocated, a beech mast has helped the mainland stoat population to boom with repercussions for Secretary Island, Ms Willans said.
''A small number of juvenile stoats have left the mainland and swam to Secretary Island - nearly a kilometre out to sea,'' she said.
DNA testing of the stoats on Secretary Island proved they originated from the mainland.
Mr Wilson said it was disappointing to discover the programme had failed but re-introducing native species was a challenging job.
Before a decision was made to have another attempt at establishing kokako on Secretary Island, DOC would attempt to eradicate the stoat threat to the birds.
''We wouldn't look at putting more kokako on the island until we have further reduced stoat numbers,'' he said.
Fiordland Lobster Company board member John Steffens said the company invested significant financial and emotional capital in the quest to bring kokako birdsong back to Fiordland.
''We are gutted by this apparent outcome, as are DOC and iwi teams who shared this dream,'' Mr Steffens said.
Despite the setback, Fiordland Lobster Company would continues to support the enhancement and protection of Fiordland's marine and terrestrial heritage, he said.
''Hopefully someday the sound of kokako will be again heard in the fiords.''
The Southland Times