As Few As 1,500 People Were Enough To Wipe Out 9 Species Of Moa, Bird Which Stood Up To 12 Feet Tall

A Haast's eagle divebombing a pair of moas. A new study finds that it only took a few thousand people to kill off the nine species of moas found on New Zealand, an act which also led to the extinction of their only predator, the Haast's eagle. Image by: John Megahan/Creative Commons 2.5.

The first settlers of New Zealand killed off nine species of giant birds, known as moas, with a population no bigger than a few thousand people, according to new research published in Nature Communications. The biggest moas stood up to 3.6 meters (12 feet) tall, making these mega-birds the largest animals in the country and contenders for the biggest birds ever.

To determine how many people it took to push the moas over the edge, the scientists started by deciphering when Polynesians first arrived on the island and began eating moa, both by hunting and stealing eggs. To do this, they conducted 93 high-precision radiocarbon dating on moa eggshells from Wairau Bar on the South Island. Experts believe this river bar was the site of the first settlement in all of New Zealand. The radiocarbon dating showed that egg stealing began within a few decades of settlement, shortly after 1300 AD.

"The analyses showed that the sites were all first occupied—and the people began eating moa—after the major Kaharoa eruption of Mt Tarawera of about 1314 CE," explained lead author Chris Jacomb with the University of Otago.

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Using population models, the authors estimated that the founding population on New Zealand was only around 400 people. By the time the moas were driven to total extinction, the population was at most only 2,500. But at the hey-day of moa hunting—before the species became rare and isolated—the population was only 1,500 people. This represents a density of just one person for 100 square kilometers. Today there's not a country on Earth with a population density so small.

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http://news.mongabay.com/2014/1110-hance-moas.html