For what was probably millions of years New Zealand was the last isolated fragment of the great southern continent, Gondwana. And then came the impact of man. The first wave was the colonisation by Maori around eight hundred years ago, resulting in mass extinction of forest browsing birds like the moa. This brought about profound changes to the land. The second wave was European arrivals, starting around two hundred years ago, which led to a whole new eco-system being transferred on to the remnants of the old. It too wrought profound changes on the land. The third wave was started by one man, Leonard Cockayne, whose obsession with browse led to a romantic desire to re-create a pristine world that had, in fact never existed. Cocayne's deeply flawed model had been powered by state bureaucracies eager to extend their departmental authority. In the beginning it was a war against deer, fought with service rifles. To-day, as a result of years of official indoctrination, the possum is the recipient of the nation's odium. 90% of the world's supply of the deadly 1080 poison is being spread on New Zealand in a misguided attempt at extermination. The Department of Conservation's obsession with 1080 has led to the killing of a few possums but many birds and other creatures; even the forest is at risk. The "third wave" of official exterminators is killing the land.