Albion Monitor /Features
 Alien Invaders: Unique problems and solutions

The Possum That Ate New Zealand

by Simone Wilson

"There are too many to shoot, and they're eating the forests"

There it is again -- a sound like someone tearing paper into strips, then shredding the strips into smaller and smaller bits. I half expect a shower of confetti to rain down on us from the unseen tops of the Kauri trees.

We're sitting on a porch in the remote Coromandel region of New Zealand, where early evening darkness obscures the estuary in front of us. Besides the murmur of our own voices and the mysterious ripping, the only other sound is a gentle, persistent popping -- a noise like milk hitting Rice Krispies -- caused by receding tide sucking at the mucky shore of Wharekawa Bay. The ripping stops. Moments later, two small eyes peer at us from around the dark bole of the tree. The eyes blink red, reflecting light from the porch. A creature like a long-legged cat with a pointy snout takes few cautious steps away from the tree, then panics and scoots back up the trunk. The confetti-making resumes. Rip, rip, rip, shred.

The creature makes a few more timid forays, skittering back to the canopy when anyone moves. Then the hostel owner closes the office across the lawn, joins the guests on the porch, and tells us the sad tail of the brush-tailed possum that ate New Zealand.

"People imported them for their pelts around 1860, but then the bottom fell out of the fur market," she explains. No longer an asset, the creatures were either released or eluded their handlers and took to the treetops. With no predators and plenty of trees of munch, the possum population exploded. Just how many possums are up there, out of sight among the treetops of New Zealand?

"Oh, about 70 million," she says with resignation. "There are too many to shoot, and they're eating the forests." If sounds are any indication, the one overhead is doing its part.

"It's a terrible problem," she concludes with typical understatement. Kiwis (as New Zealanders call themselves) don't like to sound alarmed.

For birds, New Zealand was a paradise free of predators -- until people showed up

Protected from the nearest land (Australia) by 1,100 miles of ocean, New Zealand is a living lab experiment in how to -- and how not to -- keep invasive species at bay. Apart from two species of native bats, New Zealand had no indigenous mammals when people showed up in the eighth century.

Although it's still one of the most beautiful places on earth, humans had a chance to preserve a pristine habitat but, as humans tend to do, they mucked things up.

The first big wave of settlers -- Maori sailing from Polynesia in the 1200's -- brought the Maori dog (which died out) as well as rats. Then came wave number two: eighteenth and nineteenth century Europeans whose cattle, hogs, chickens, goats, rabbits, deer and ring-necked pheasants tagged along. Later the immigrants imported other species, including the Australian brush-tailed possum. A distant cousin of the wallaby and the kangaroo, the brush-tailed possum is actually a marsupial with a long, fuzzy tale, pointy snout, and a good-looking pelt the Aussies like to call "Adelaide chincilla."

With no snakes or predator mammals to eat them or their eggs, New Zealand's native birds had flourished. Once animals came, however, birds were harried by the new arrivals. Some species disappeared; others, including the namesake Kiwi, dwindled to perilously low numbers. Many birds, like the iridescent blue Takahe (a fat, lumbering cousin of the moorhen), died out except on the smaller islands or at high elevations. Today, however wildlife federations are trying to reverse the trend and boost the populations of endangered species by introducing them to sheltered reserves.

On a bright, steamy fall day, with the humidity fast catching up with the temperature, I take a launch out to Mokoia Island, 650 acres of tangled jungle. Within half an hour, I spot two of the Mokoia's famous imports: the saddleback and the stitchbird. Both were extinct on the North and South Islands until reintroduced by government ecologists. The saddleback had survived only on Hen Island; the stitchbird had vanished except on Little Barrier Island. Both birds are slowly building up their numbers on Mokoia Island, which has no resident mammals except the horses, who are content to eat the grass. For the birds, it's a paradise free of predators -- as all of New Zealand was before people showed up.

Today the Kiwis are scrupulously careful about importing things; tourists arriving by boat or plane must declare anything remotely organic: nuts, baskets, wooden curios. New Zealand is also the only place where airline stewards file up and down the aisles and spray you before you're allowed to get off the plane, in case ladybugs or even more sinister beings are hitching a ride. You can't be too careful when you're protecting paradise, even if you're getting a late start.

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Albion Monitor March 10, 1996 (

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