We are lucky to have quite detailed knowledge about Tikopia, thanks to the anthropologist Raymond Firth, author of We, the Tikopia, and the archaeologist Patrick Kirch, author of On the Road of the Winds. Sometime between the years 1000 and 1800 AD, instead of "losing it," the Tikopians responded by making three ecologically-driven decisions" First, they limited their population" Second, they shifted from slash-and-burn agriculture to permaculture, growing multi-storied orchards of fruit and nuts" Third, sometime in the 18th century, before white contact, they gave up keeping and eating pigs".
Source: Dauncey, Guy, World Watch, Vol. 16, No. 6, November/December 2003, 5.