Call it the kokako cold case. The fate of the South Island kokako, long a mystery, was thought concluded when the bird was officially declared extinct six years ago.

But hopeful bird watchers who have beaten through southern wilderness to find it have been heartened by its surprise re-classification from extinct to "data deficient" - with not enough information to be certain of its demise.

This came after a claimed sighting by two people near Reefton in 2007 being accepted by the Ornithological Society's Records Appraisal Committee, which monitors the status of rare and endangered birds.

The last accepted sighting of the South Island kokako - distinguished by its haunting call, orange wattle and long, lean legs - was in 1967.


Yet a number of people have claimed to have sighted it since.

South Island farmer and Forest and Bird member Alec Milne says he has both heard and seen the lost bird.

"The defining moment for me was in a small alpine valley at the head of the Cobb Valley, listening to notes that hung in the air then echoed off the rock faces - the injustice of turning our backs on such a bird, it having recently been declared extinct, I found unacceptable."

Mr Milne, who now runs a project partly funded by the group to find evidence they still exist, described the reclassification as "wonderful".

But Pete Shaw, who was part of a 2008 expedition to find it, isn't so convinced the bird has escaped extinction.

After receiving a promising report, his team ventured into the Waitutu Forest in the lower South Island, but found the so-called kokako calls to be kaka with "a very odd local dialect".

"I'd say quite confidently that there's nothing like a viable population, or even a pair, left in New Zealand, but there might be the odd single bird," he said yesterday.

The Reefton sighting was one of 11 such sightings submitted, but the others, from the Marlborough Sounds, northwest Nelson, the West Coast and the Catlins, between 1990 and 2008, were considered to be only "possible" or "probable".

Forest and Bird advocacy manager Kevin Hackwell said that while it couldn't be confirmed the South Island kokako was still alive, "this is the best sign yet that it is".