Easter Island, Tikopia, and the choices we have.

• Author: Dauncey, Guy
• Position: From Readers - Letter to the Editor

In "What Is Sustainability, Anyway?" (September/October 2003), Thomas Prugh and Erik Assadourian invite us to learn from the awful lessons of Easter Island, where the inhabitants overharvested the trees, deforested the island, ceased being able to make big canoes, and were no longer able to fish the deeper offshore waters. With no forest, the soils eroded, their food surpluses disappeared, warfare erupted, and the population collapsed.

The lessons that the authors draw are that humans seem wired to overuse abundant resources; that we take bounty for granted and fail to see when things are going wrong; and that when the food begins to run out, this can undermine the organizational capacity we need to fashion a response.

As a parable, the fate of Easter Island doubtless appeals to those who have a gloomy mindset. There are other parables, however, which we can also consider. A few thousand miles to the west is another small island, Tikopia, whose inhabitants also expanded their population too far, and who also ran up against their ecological limits. 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. An Archaeological History of the Pacific Islands Before European Contact (2000). 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 to around 1,700 people, the most the island could sustain. They only allowed first-born sons to marry and have children; other sons could have partners, but not children; they used abortion and infanticide to uphold their policy of zero population...