Stephens Island is a tiny, windswept patch of land in the Cook Strait, wedged between New Zealand's North and South Islands, and for more than a century it has been remembered for one particular story, a cat supposedly wiping out an entire species of bird almost single handedly. The bird in question was Lyall's wren, a small, flightless songbird found nowhere else on earth, and the cat was Tibbles, brought to the island in 1894 by assistant lighthouse keeper David Lyall.