New Zealand was originally a land of birds before the introduction of animals like possums and stotes - now a national subject of hatred. As a result of being inhabited mostly by birds, some of the birds lost the power of flight (for example the Kea and the Kiwi) because there was no threat/predator to fly away from. Likewise the native trees have not developed a toxin to resist being gnawed away at. The possum and other animals are now hated because they kill the birds/eat their eggs and destroy the native trees. The Kea bird here is becoming endanged. See how much I've learned?