The history of stoats and rabbits in New Zealand is a great example of what happens when species are introduced to islands. Read the sad, instructional tale here.
The wildlife of New Zealand thrived in the absence of people for millions upon millions of years. Then within a few hundred years people changed everything. People brought plants and animals to these islands that had never lived here before. Some were benign and others turned out to be catastrophic mistakes. Introducing stoats turned out to be a big error that actually began by bringing cute, cuddly rabbits to New Zealand.
Rabbits Quickly Became A Problem In New Zealand
Rabbits were introduced by the early European settlers for food and their skins. These first introductions took place in the 1840s, roughly when Europeans began arriving in New Zealand in large numbers. Rabbits lived up to their reputation and began reproducing and spreading quickly.
In fact, by the 1880s (in only 40 years) rabbits had become so widespread that they became considered a serious pest and are still so today. They threaten the New Zealand economy due to their direct competition with livestock to eat grass. Rabbits also cause serious land damage by making burrows and can ruin agricultural land.
People Sought Biological Controls Of Rabbits – They Introduced Rabbits’ Predators
Yes, so people had brought rabbits to New Zealand because they wanted them for food and their skin. That didn’t work out too well because rabbits had never lived here before and there were no natural predators.
Thus, some people came up with the idea that they needed to bring some of rabbits’ natural predators to the islands to help solve the rabbit menace. In other words, people started bringing stoats, ferrets, and weasels to New Zealand in the 1880s.
Stoats, Ferrets, And Weasels Became Their Own Problem
Surprisingly, or maybe unsurprisingly, the introduction of these mammalian predators turned out to not be such a good idea. Stoats and the others did kill some rabbits, but they were not the silver bullet, cure all, that people hoped they would be.
Worst of all, the introduced stoats, ferrets, and weasels also began killing off the native New Zealand birds. Stoats are very efficient predators that hunt and kill the prey that they can find.
In New Zealand they found lots of small birds, many of which were even flightless. They must have been pretty happy to have arrived in this country where they had no enemies to be worried about and an abundance of food!
Stoats are now widespread all over the islands of New Zealand and are listed as one of the big three predators. Huge efforts of time and money have been spent and are still spent trying to eradicate them in order to protect or bring back native birds, reptiles, and insects.
The Law Of Unintended Consequences
Back when I was in university I remember learning about the law of unintended consequences. As I recall it, the basic premise is simply that it’s impossible to predict all possible outcomes. There will always be some unintended consequences.
It seems that the history of people introducing plants and animals into New Zealand is a perfect example of this law of unintended consequences in action. Time and time again people brought some species, be it rabbits or stoats, to these islands and the results were not what they thought or hoped they would be.