Possums have been a thorn in New Zealand's side since the day they arrived. That's because, for 80 million years, this South Pacific nation was a land of
birds -- flapping, singing, deafening, glorious. "The most melodious wild musick I have ever heard," journaled Captain Cook's botanist, Joseph Banks, in 1770. Then Europe brought
the invasive species.* Off the boat they scampered, into what must have seemed like possum paradise: a green Eden filled with tender trees and land-dwelling birds
more tasty than hasty.

Two gulls on Kapiti Island, a nature preserve three miles off New Zealand's coast that has been wiped clean of mammals. [
Rachel E. Gross]
Massacre was swift. Today, many consider possums Public Enemy #1. It isn't that they're more destructive than, say, cats (which we now know are secret serial killers); they aren't. It's that there are 30 million of them in
a country the size of Colorado. They chomp on wide swaths of forest, kill millions of birds and chicks a year,
and go around spreading bovine tuberculosis to cows. "They've whittled our wildlife away," Toki said mournfully. Plus, they're Australian.
For these reasons, New Zealand has been chipping away at their demise. It's managed to clear possums and other mammals from more than a hundred offshore
islands. It's created wildlife havens ringed with fences, where the spotted kiwi once again waddles in peace. There's even a campaign called Million Dollar Mouse, started by cat-hater and
economist Gareth Morgan, that aims to remove rodents from the Antipodes Islands.
What would it take to tackle the mainland? "It would be a military operation," predicts Charles Daugherty, an ecology professor at Victoria University who
joined Toki at a radio forum called "Kill a Stoat, Save New Zealand"
last August. The government already rains thousands of pounds of a controversial poison onto hard-to-reach forest every year, just to keep pests at
bay. To kill them all, Toki imagines "a series of rolling fronts" consisting of guns, traps, and more poison.
Such a feat won't be cheap: a government report last
month put it north of $25 billion. But don't underestimate how much New Zealand loves its wildlife. Every morning, the country tunes in to Radio NZ for a special minute of birdsong before the news. There is a "national appetite" to return the country
to its original avian paradise, Daugherty said. And many believe it could be done. After all, New Zealand has been leading the world at killing things for
25 years.
When it can, though, it tries to do so humanely. After all, are possums not also of the kingdom Animalia, class Mammalia? Are not their bodies four-legged,
their hearts four-chambered? If you suckle them, do they not lactate? If you prick them, do they not warmly bleed? "Just because they're a pest doesn't
mean we shouldn't be concerned with minimizing their distress," said Kate Littin, a government adviser on animal welfare.
Plenty of New Zealanders couldn't care less what a possum feels. But some do. Littin wants the example her country sets for the world to be one of
"compassionate conservation." After researching the effects of the poisons used on rats and possums, she helped come up with a framework of relative humaneness for
pest control that's now being used on rabbits across Australasia. "It's not a revolution," she said. "But it's an evolution."