Researchers have proven that Kiwi, the flightless bird of New Zealand, is not a migrant from Australia, according to a new study.
The DNA study was conducted by the University of Adelaide, where they determined that Kiwi's closest relative is an extinct giant bird of Madagascar, not the Australian emu, as they previously believed.
The study was published in the journal Science today, May 23.
The flightless giant elephant bird of Madagascar stood 10 feet tall and weighed over 600 pounds. The study showed that both birds, which went extinct a few centuries ago, once flew, according to a University of Adelaide press release.
"This result was about as unexpected as you could get," Kieren Mitchell of the University of Adelaide's Australian Centre for Ancient DNA, or ACAD, said, in a statement, according to the release.. "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."
Giant flightless birds, like ostrich and emu, fall under the "ratite" category, which also contains some of the world's largest birds, like the extinct giant moa of New Zealand, and the elephant birds of Madagascar.
For the study, the researchers examined ancient DNA taken from the bones of two elephant birds and found a close genetic connection with the kiwi, despite significant differences in body shape, lifestyle, and size, according to the release.
Since both birds lived some 7,000 miles apart, the researchers used the elephant bird DNA to estimate when the ratite species separated from each other.
"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," Alan Cooper of the University of Adelaide said, in the statement according to the release. "We think the ratites exploited that narrow window of opportunity to become large herbivores, but once mammals also got large, about 50 million years ago, no other bird could try that idea again unless they were on a mammal free island - like the Dodo."
The researchers also confirmed that they found fossils of small kiwi ancestors that likely had the ability to fly, meaning kiwis were flying when they reached New Zealand.
"By the time it arrived in New Zealand, the large herbivore role was already taken by the moa, forcing the kiwi to stay small, and become insectivorous and nocturnal," said Trevor Worthy of Flinders University in Adelaide, according to the release.