This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
New Zealanders love their kiwis. Not only does the flightless bird appear on New Zealand's currency, but New Zealanders identify themselves as "Kiwis." Which would make it even more painful if the country's national symbol became extinct.
That's the danger these days as all five species of kiwi (from the genus Apteryx) are endangered, and disappearing rapidly. Recent surveys by the New Zealand Department of Conservation found that kiwi populations are shrinking by 6 percent a year, mainly due to predation by European stoats (Mustela erminea).
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Stoats, also known as ermines or weasels, were first introduced to New Zealand in the 19th century to combat another introduced species, the rabbit, which has caused great environmental damage throughout Australia and New Zealand. But the stoat stubbornly refused to restrict its diet to rabbits, and defenseless young kiwi chicks make attractive meals.
As stoats extend their range throughout the island nation, the populations of kiwis have crashed. Little spotted kiwi (Apteryx owenii) populations have dropped to 1,200 birds, and the Rowi or Okarito brown kiwi (Apteryx rowi) has just 300 individuals left.
Unfortunately, stoats are very hard to catch. "The animals are so abundant and resilient that trapping has been abandoned as a control measure," reports The Australian newspaper.
Instead, Kiwis are resorting to breeding programs to protect their kiwis. Fertilized eggs and young chicks are being removed from the wild, then returned when they are old enough and big enough to defend themselves. This has already been enough to boost rowi populations by 45 new birds. "Rowi are literally being brought back from the brink of extinction," Department of Conservation regional director James Livingstone told The Australian.
Meanwhile, some New Zealand farmers are taking matters into their own hands. On New Zealand's Okahukura Peninsula, connected to the mainland by a sliver of land, farmers are waging all-out war against stoats and other introduced species like possum. One hunter, Bill Pikea, tells The Rodney Times that he has killed 16,000 possum in the past seven years. (Possum carry bovine tuberculosis, a threat to local beef farmers.) It hasn't been enough to boost kiwi populations on the island quite yet, but the locals say they don't think it will be much longer before kiwis start wandering free again.
Image of the kiwi bird (first) courtesy of Maungatautari Ecological Island Trust via Wikimedia Commons; image of the stoat (second) courtesy of Steve Hillebrand/USFWS via Wikimedia Commons
