NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665
February 10, 2000
Tom Isern, Professor of History
North Dakota State University
©2000 Plains Folk
This scene I'm about to describe, from far away in 1991, I remember well. I was standing in the middle of a venerable sheep station--what we would call a ranch--in the middle of the Mackenzie basin in the middle of the South Island of New Zealand. The station proprietor, all khaki, felt and leather, looked about from rim to rim and told me how his property, indeed almost the entirety of the Mackenzie, had been turned into desert by rabbits and hawkweeds.
The culprits were European gray rabbits, introduced intentionally a century and a half ago, and Hieracium pilosella, a yellow-flowered, fuzzy-leafed matweed that came from Eurasia by means unknown. There had been no sheep on the station for the past five years--grazing pressure was not the issue--but nature was not healing itself. Things were just getting worse.
I saw how bad things were when I looked down at my feet. There was no grass, clover or useful forage of any kind. I was standing on a 3-inch-thick layer of bunny excrement. The only green peeking through was a few tawny spears of hawkweed, reclaiming the ground from one useless state into another. Here and there lay an empty 12-gauge casing.
Here on the Great Plains of North America we have our share of pests and weeds, the worst of which are introductions from Eurasia. Our natural systems, though, are comparatively strong. They have diversity and hardiness. Things are worse in a country like New Zealand, an island where the natural systems evolved in biological isolation. Its birds never knew predators, its grasslands never knew the tread of grazing animals, its trees and shrubs never felt the teeth of browsers until Europeans arrived. With the colonists came all their plants and animals, and things have been a mixed-up mess ever since.
Here is a partial listing from the rogue's gallery of pests and weeds plaguing New Zealand: English sparrows, Canada geese, wild pigs (tasty but destructive), red deer (real forest killers), Australian possums (also forest killers, and carriers of bovine tuberculosis), rabbits, hawkweeds, Californian thistle (what we call Canada thistle), nassella tussock (unpalatable grass from Argentina), blackberry (a sheep-killer), and gorse (living fence plant from England, thorny, beautiful but aggressive).
It was my task to write the history of all these pests and weeds for the Oxford Environmental History of New Zealand. I guess it's appropriate that I, the only foreign author in the book, got the job of writing up the foreign pests and weeds!
The rabbit nuisance, as the situation is called, is the case most interesting to me, because it's a matter of the semiarid grasslands, like my own American plains. During my previous visits to New Zealand in the 1990s, I observed a tragic outbreak of rabbits. The agricultural economy was depressed, and people lacked the means to keep the bunnies under control. Still, I observed them dropping tons of poison baits from the air and also going after the critters, night-shooting from landrovers and all-terrain vehicles, using shotguns and laser sights.
All that changed in 1997, when someone, no one knows who, smuggled in a biological control called the calicivirus. Previously someone had sneaked the virus from China into Australia, where it killed rabbits by the millions. New Zealand had considered bringing it in, but decided not to--popular sentiment was against bringing in any new organisms from abroad. That led some individual to take action.
I'm told there is hardly a rabbit to be seen in the country I had seen devastated. When you read this, it's a good chance I'll be out in the sheep stations, looking over the situation for myself.
Source: Tom Isern (701) 231-8339
Editor: Dean Hulse (701) 231-6136