Possums invaded what they thought was an island paradise. Now numbering near 30 million in a country the size of Colorado, they are hated with a passion fueled by national identity and bovine tuberculosis.
It sucks to be a possum in New Zealand. Cars swerve to hit you. Guns point toward you. People feed you little green pellets that taste like cinnamon, only afterwards they taste like poison death. Plus, no one ever gets your name right.
But if you are a possum, brace yourself: it's about to suck more. New Zealanders are rallying to launch an all-out war against their furry foes, following a scientist's dying vision for a "Pest-Free New Zealand." Those pests include (take a breath): rabbits, rats, weasels, cats, stoats, goats, deer, and hedgehogs ... but mostly, possums. "It's a pretty easy sell," said zoologist Nicola Toki, a passionate supporter of the plan who works for the Animal Health Board. "We relate our national identity to our native wildlife. And everybody hates possums."
Islands make up 3 percent of the world's landmass, yet they harbor a massive fraction of its species. Many of those species are uniquely vulnerable to invaders, e.g. possums. To wipe out mammals on islands as big as those of New Zealand would be "a huge challenge," said Dan Simberloff, an invasion biologist at the University of Tennessee. But if they pull it off? "It'd be the greatest triumph of invasion management the world has ever seen." In other words, New Zealand could serve as a beacon of hope to threatened biodiversity hotspots worldwide, like Hawaii and the Galapagos islands.
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.
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.