trouble in paradise

On Ulva Island (Te Wharawhara in Maori) you (almost) experience the world as it was 85 million years ago.

Ulva Island is a tiny island (3.5 kms or just over 2 miles in length) - home to a large number of birds, invertebrates and plants endangered elsewhere in New Zealand.

The island is a ten minute ferry ride from Stewart Island (Rakiura in Maori). Stewart Island is a one hour ferry ride from the southern tip of New Zealand's South Island. It's separated from the southern continent of Antarctica only by an expanse of sea and ice. The climate is cool temperate.

Ulva Island has been described as a primeval paradise, rich in biodiversity, and it is. However, (as you would expect), there is trouble in paradise.

New Zealand separated from the supercontinent of Gondwanaland before the evolution of mammals. Hence there are no mammals native to New Zealand. The Maoris arrived from Polynesia 700 years ago and later came the Europeans. With the Europeans came cats, rats, possums, ferrets and stoats. The native birds didn't have a chance against these introduced predators and rapidly diminished in numbers. In addition there was widespread destruction of their habitat as trees were felled.

Gradually there grew a new consciousness about the importance of environmental conservation. In 1899 an impressively progressive New Zealand government reserved most of Stewart and Ulva Islands to preserve 'native game and flora'.

Of all the introduced predators rats were the worst, eating almost anything - seeds, seedlings, eggs, chicks and fruit. There used to be thousands of rats on Ulva Island, but by 1997 it was believed that there were no more rats, due to a longterm vigorous and intensive eradication program.

Unfortunately the rats have returned. Another determined onslaught is needed and has begun.


  1. Good post. Its difficult when an ecology is disturbed with a powerful new predator. Humankind is often the same,

  2. Years ago New Scientist wrote that New Zealand is so isolated that there are plants as if from another world.
    Our sunbirds don't hover as much as hummingbirds do. Mother Nature gave ours plants they can perch on ;~)

  3. Great post Catmint! It is a pity that we so often learn in hindsight. We so often carry undesirables in our baggage. I hope they are able to get the rat problem under control quickly this time. Your photos make me want to be there.

  4. Hi Catmint, that's so much for your visit to my blog :)

    I have been to NZ several times now, and I remember when I was there learning that the introduced possum was a pest. Isn't it amazing what works so well in one country can be a total disaster when you introduce it to the country just next door.

    I do so hope their rat eradication program works, I am trying for the same thing, but on a slightly smaller scale at my houseblock!

  5. Rats... not my favorite creatures!
    I'm told we have 5 types ... small to very large, in my little town.
    I can only wonder where they all originally came from.
    Hopefully the rats you mention on that tiny NZ island can be brought under control. Very sad to hear this.

  6. It so sad that everytime a new species which is not native to any area will be so destructive for the natives.

  7. Hi Hermes, yes!!!!!! humankind is the worst pest of all.

    Hi Diana, the plants are as if from another world. It was a magical place.

    Hi Carol, if at all possible try to go there, it is an amazing and wonderful place.

    Hi Ali,yes I bought my grandson a possum fur hat because they hate possums there but I love them here. I did wonder how a 2 year old will deal with that inconsistency.

    Hi Alice, I think they will never completely eradicate them but it's still a wonderful place and many endangered species of birds and plants are doing OK there.

    Hi MKG, I think not everything that is not native is not necessarily so destructive but rats certainly are.

    cheers, catmint

  8. Very interesting post but sad. Invasive species is a problem all over the world. Rats being omnivores would be especially nasty. They are intelligent and adapt easily. A hard battle to win, but one that had be won before.

  9. wow. how interesting and depressing. I guess I don't have much against rats, but any incredible boom in such a destructive pests population - it's scary.

  10. We humans do have a sad tendency to wreck the ecology of any new place we settle. I haven't seen our native red squirrel since I was about 6 years old - and that is a long time ago now - and Japanese Knotweed is a terribly pernicious plant. Rats though, as imported pests go those have to be amongst the most unpleasant.

    Thanks for visiting my blog, glad to have found yours.

  11. This looks like a perfect place for relaxation. I love the greens - they are pleasant to the eyes and bring so much fresh air to the lungs ;-) You must have had the most pleasurable time there yeah. I hope the rat problem will be solved soon. I think they multiply quite fast.

  12. I've always wanted to visit New Zealand. I didn't know there were no mammals native to there- you learn something new every day! I especially like the 2nd and 3rd photos- stunning!


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