Given the many problems caused by humans to the various species living on Pacific Islands, their rapid decline seems inevitable, but to a degree this process was happening naturally, long before we showed up. Such losses and gains were, and still are, dependent upon many factors, but as a general rule, smaller islands exhibit a greater turn over than do larger islands; and the arrival of man has now pushed the losses to the level of a major extinction event, with both New Zealand and Hawaii exhibiting clear examples of the problem.  I mentioned Hawaii's carnivorous caterpillars in a previous…