Why our cats are a danger to species diversity and human health In 1894, a lighthouse keeper named David Lyall arrived on Stephens Island off New Zealand with a cat named Tibbles. In just over a year, the Stephens Island Wren, a rare bird endemic to the island, was rendered extinct. Mounting scientific evidence confirms what many conservationists have suspected for some time--that in the United States alone, free-ranging cats are killing...