Flightless parrots, burrowing bats, giant skinks and kangaroos in trees - on the isolated islands of the South Pacific, the wildlife has evolved in extraordinary ways. But island living can carry a high price, for when new species arrive, all hell breaks loose. And there lies a puzzle: why do animals perfectly adapted to island life simply give up the ghost? The answer is revealed by the remarkable stories of some unlikely animals that survived on tiny islands off the coast of New Zealand.