WASHINGTON - New Zealand's iconic kiwi is most closely related to the extinct elephant bird of Madagascar rather than the Australian emu as previously thought, researchers said Thursday.
The findings stem from a study by the University of Adelaide that was based on ancient DNA analyses of elephant bird bones at the Museum of New Zealand, Te Papa Tongarewa.
At two to three meters (6.5 to 10 feet) tall and weighing in at 275 kilos (600 pounds), the Madagascan elephant bird was a far cry from the chicken-size kiwi.
But the DNA analyses revealed a close genetic link between the two.
What's more, the study - published in the journal Science - found that both of these flightless birds once took to the skies.
And that, the researchers say, has helped solve a 150-year-old evolutionary mystery about the origins of giant flightless "ratite" birds found across the southern continents today, such as emus and ostriches.
"This result was about as unexpected as you could get," said researcher Kieren Mitchell of the University of Adelaide's Australian Centre for Ancient DNA (ACAD).
"New Zealand and Madagascar were only ever distantly physically joined via Antarctica and Australia, so this result shows the ratites must have dispersed around the world by flight." The findings apparently correct previous research carried out in the 1990s that had pointed to the Australian emu and cassowary as the kiwi's closest living relatives.
"It's great to finally set the record straight, as New Zealanders were shocked and dismayed to find that the national bird appeared to be an Australian immigrant," ACAD Director Alan Cooper, who carried out the 1990s research, said in a statement announcing the new findings.
The researchers used the elephant bird DNA to estimate that the ratite species separated from each other shortly before the dinosaurs became extinct some 65 million years ago.
"The evidence suggests flying ratite ancestors dispersed around the world right after the dinosaurs went extinct, before the mammals dramatically increased in size and became the dominant group," Cooper said.
Researchers also said they recently found fossils of kiwi ancestors that confirm kiwis were capable of flying when they arrived in New Zealand.