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  • Rights: The University of Waikato
    Published 3 November 2009 Referencing Hub media

    Dr Phil Bishop, from the University of Otago, talks about our native frogs and some of the reasons they are so vulnerable to extinction. He describes the process of assigning a conservation ranking or threat status to a species.

    Point of interest: Imagine you are on the expert panel. Make a list of the factors or criteria you would look at to help you decide how to rank a species according to their conservation status.

    Jargon alert: IUCN stands for the International Union for the Conservation of Nature. They administer the international Red List of Threatened Species.


    New Zealand frogs are very special frogs, and there is no doubt about that in the scientific world. They are vulnerable mainly because of their very sensitive skin. So they are very vulnerable to changes in the environment, in the soil, in the moisture, in the air, in the water. They are just incredibly sensitive. They are the environmental monitors, and if frogs start to disappear, then it really means we are mucking up the environment and we need to stop and take a good look at what we’re doing to our own environment because it’s going to ultimately impinge upon our welfare.

    When something becomes extinct, it’s a very serious situation because it’s gone forever. And nowadays, what we are trying to do – because extinction is inevitable, and 99.9% of species that have ever existed have become extinct – but one of the things that we worry about with amphibians is that the rate of extinction is much much greater than it ever has been.

    For a conservation threat status, what we do is that we get a panel of experts – New Zealand experts that are experts on this particular species – and there is a list of very important criteria that we have to judge that population on. I have just come back from a day’s meeting in Wellington where we had this expert panel at DOC Headquarters, and we all sat around and we worked out all the new threat classification rankings for all of New Zealand’s frogs, and we go through each frog individually and we work out the area of occupancy, how many individuals are left, what are the threats, what are the likely threats and all those sorts of things, and then we go through the certain criteria and we come up with a ranking, and that then gets submitted to the International Conservation Union, and that gets published as the international conservation ranking for that frog.

    A.Haigh, Department of Conservation. Crown Copyright 2009
    Prof. Ben Bell, Victoria University of Wellington
    Jennifer Barnard
    Keven Law

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