A new family of indigenous New Zealand birds has been created after a crucial discovery aided by the curator of Auckland Museum.
Curator Dr Brian Gill and an international team of scientists have discovered that the stitchbird or "hihi" belongs to a family of its own and has no close relatives.
For years it was widely held that the stitchbird was part of the tui and bellbird family of honeyeaters.
It was given the name Notiomystis cincta when discovered in 1908, derived from Greek words meaning "southern mystery" because even then it was thought a somewhat strange little bird.
Now the mystery has been solved after the team comprising molecular biologists and museum staff from the United States, Australia and New Zealand have confirmed the stitchbird has no close relatives and is actually in a family of its own.
There were thought to be only three surviving families of endemic New Zealand birds (birds only found here): kiwi (Apterygidae), New Zealand wrens (Acanthisittidae) and New Zealand wattlebirds (Callaeidae).
Six years of research has now proven there is a fourth - the stitchbird (Notiomystidae).
Dr Gill, curator of birds at the Auckland War Memorial Museum, said the discovery of a new bird family was rare and exciting.
Dr Gill said it had been thought the stitchbird belonged, with bellbirds and tui, to the honeyeaters family (Meliphagidae), which was not endemic to New Zealand as species were also found in Australia and elsewhere.
The stitchbird was a similar size to the bellbird and had a similar beak, taking nectar from flowers with a brushed tongue.
"But there has always been something unusual about the bird in its behaviour and appearance, so it was thought of as an odd honeyeater."
Dr Gill said in 2001 an American PhD student, Amy Driskell, was researching her thesis on the molecular biology of about 180 species of honeyeaters when she sampled a stitchbird's DNA and found it did not fit with the others.
Dr Gill sent her more samples from museum birds and the results confirmed the stitchbird was not from the same family tree.
The question arose as to what family tree the stitchbird fell into, and the closest relationship pointed to the wattlebirds, which included the kokako and saddleback.
"But we could not put it into the wattlebird family because it has no wattles."
Dr Gill said the research also showed the split from wattlebirds happened about 30 million years, so it was decided the stitchbird had its own family. "It is very unique, it represents its own whole family."
Dr Gill said the discovery showed the strong relevance of museums and taxonomy and would add to the impetus to manage the rare and endangered bird, whose population was slowly recovering after shrinking to just a small population only found on Little Barrier Island.
Other populations were now being established on Kapiti and Tiritiri Matangi islands, the Pukaha Mt Bruce National Wildlife Centre, and the Waitakeres.