I did read somewhere that after they moved to NZ, there was nowhere else to go - there had been a repeated practice of island hopping: as they arrived at each island, they ate all the eatable creatures on the island, so then they moved to the next. Once they arrived at NZ, consumed all the animals and birds, they then turned of each other. This was only just before the whities arrived.
This version may not be true - I think I got it from Jared Diamond's books 'Guns Germs and Steel' or 'Collapse' - when these books were being discussed in the media a little while back.
Hmmm, I hadn't read that about cannibalism-by-necessity. One of the articles I read stated that the Maori, as opposed to other Polynesian cultures, ate-whom-they-ate as an insult to that person, not as an honor. So it sounded like an act of aggression. (Who knows?)
But I did read that they hunted to extinction at least one of the species on the island: a 3-foot high flightless bird called the moa.
Hunting gave way to agriculture, and full-time warriors became part-time warriors -- even in their wars with the British.
About the island-hopping ... there's a whole can of worms right there. Towards my closing point of reading (to be continued later), I had just come upon these sites/literature claiming that there was a civilization there prior to the arrival of the polynesian tribes. It was posited that the roots were Celtic --- and that in the oral mythology, there was reference to the fair-skinned/white-skinned old peoples.
It intrigued me, because one of the Maori elder-clips I found (the woman) made reference to the fact that "we have always been here..."
Many unsolved mysteries. (Just the way I like it, heheh.)