KEY POINTS:
A hunt for a native bird thought to have disappeared has failed.
Bird calls many believed were those of the extinct South Island kokako were the call of the kaka.
A team of conservationists this month searched the Waitutu Forest and the west branch of Big River in the lower South Island hunting for the kokako, which has not been seen for 40 years.
The bird was declared extinct last year, though calls, occasional sightings and the discovery of feathers have been documented since the late 1980s.
Researchers were excited by a number of bird calls recorded by the team, but they were almost certainly made by kaka, search team member Simon Hall said.
The team heard kaka make similar tones among their identifiable calls, the calls were often made at night and were solitary and isolated, whereas kokako usually responded to other calls.
There were no responses to recorded calls by the still living North Island kokako.
Mr Hall said it was likely the South Island's kaka population used to mimic the kokako call, and it was probable they had developed a dialect that still incorporated the kokako song.
The team is now investigating reports of three kokako near Lake Carrick.
