It has been labelled the world's ugliest bird, and now kakapo has been named one of the most unique and endangered.
In a just published article in Current Biology, researchers ranked the world's 10,000 recorded bird species by how evolutionary distinct they were and their risk of extinction.
A list of 100 Evolutionarily Distinct and Globally Endangered (Edge) species was produced, on which eight New Zealand birds were listed, including kakapo, kokako and black stilt.
By looking at avian evolutionary trees, researchers worked out which birds were the most genetically unique.
For instance, the South American oilbird, a small nocturnal bird, and the cuckoo roller of Madagascar are both separated from all other birds by more than 65 million years of evolutionary history.
Yale University evolutionary biologist Walter Jetz, one of the article's co-authors, said distinctness showed how much would be lost if a certain species went extinct.
"If there is only one of a kind, say an oilbird, and it were to go extinct, all the information on how to make and be that species would be lost forever."
The information could help with targeted conservation because there was not enough funding to protect all vulnerable species.
There have also been lists for mammal and amphibian Edge species. All four species of native frogs were on the amphibian list, with Archey's frog listed as number one.
Top rankings of NZ birds by uniqueness and threat of extinction:
4. Kakapo: The only flightless parrot in the world, kakapo are intensively managed on offshore islands.
14. New Zealand storm petrel: One of the smallest seabirds in the world, the species was thought to be extinct until one individual was found in 2003. Last year, researchers found breeding sites on Little Barrier Island.
43. Kokako: A South Island subspecies was assumed extinct, but possible sightings in 2007 have raised hopes it might still be around.
- The Press
Is this the best summer ever?Related story: Wellington sizzles in January heat