Even a population of a mere 2,500 people living in New Zealand managed to kill off moa, a now-extinct flightless bird, according to a recent study.

Normally you may think that it would take tens of thousands of people and countless years of hunting to erase an entire species, but for the moa all it took was fewer than 1,500 Polynesian settlers in New Zealand and a little more than a century. Eventually, these settlers numbered around 2,500 by the time moa went extinct.

Astonishingly, this is one of the lowest human population densities on record for any pre-industrial society.

The first evidence of moa hunting came from analyses of eggshell pieces found from first settlement era archaeological sites in the eastern South Island of New Zealand.

"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," researcher Chris Jacomb explained in a press release.

So according to the new findings, which appear in the journal Nature Communications, the Polynesians' taste for moa (Megalapteryx didinus) led to their demise. When moa and seals were still available, the better diet enjoyed by the settlers likely fueled higher population growth.

At first the human population started at about 400 people at the beginning of the 14th century, and radiocarbon dating of the moa eggshells shows that only about 100 years after that did the moa species become extinct.

Researchers have long contended that humans could not be blamed for the extinction of other species, including the mammoths and giant sloths of North America and the giant marsupials of Australia. Supposedly this is because those populations were just too small to cause that great of an impact.

However, the study's results and the extinction of the moa - along with the giant eagle and giant geese - suggest otherwise, proving that human population size is a factor that can no longer be ignored.