Giant moa thrived before people reached New Zealand

DNA data suggest flightless birds went extinct because of human activity

Humans probably caused the extinction of giant wingless birds called moa in New Zealand, DNA evidence suggests.

Scientists have debated why the several species of moa went extinct about 100 years after Polynesians settled New Zealand around A.D. 1300. Various lines of evidence suggest that people’s hunting, setting fires and bringing competing species to the islands caused the big birds’ demise. But recent genetic evidence hinted that moa were declining before the Polynesians ever reached New Zealand. The birds may have been victims of disease and volcanic eruptions that reduced their numbers and genetic diversity.

Now, an international group of researchers has analyzed more complete DNA records from fossils of four species of moa. The fossils range in age from around 600 to 13,000 years old. The researchers saw no evidence of decline in the birds’ genetic diversity over the last 4,000 years of their existence. In fact, the population of one species, Dinornis robustus, increased, the team reports March 17 in the Proceedings of the National Academy of Sciences. The new findings point to humans as the reason moa went extinct.

Hunting and other human activities probably caused giant wingless birds called moa to perish. Before people reached New Zealand about 700 years ago, the birds were doing well, new DNA evidence suggests. The moa went extinct within about 100 years of humans’ arrival. Joseph Smit/Wikimedia Commons

Tina Hesman Saey is the senior staff writer and reports on molecular biology. She has a Ph.D. in molecular genetics from Washington University in St. Louis and a master’s degree in science journalism from Boston University.

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