For conservation biologist Holly Jones, one of the best experiences of her work on island wildlife was the night she went out hunting for a rare lizard-like creature called the tuatara on Stephens Island in New Zealand. The place was cacophonous with seabirds, which also happened to be attracted to her headlamp. At one point, she found herself sitting in the dark with birds in her lap, at her shoulders, and flapping endlessly around her head. It was like Hitchcock’s The Birds, she said, except that she was ecstatic to be part of this island explosion of life.
Stephens Island happens to be the site one of the most notorious episodes in the history of humanity’s enraptured—but rocky—affair with islands. In 1894, a crew of lighthouse keepers arrived there, bringing a cat named Tibbles with them. The cat was soon coming back to the lighthouse with small, flightless birds in its teeth. One of them turned out to be a new species, the Stephens Island Wren. Within a year or two, a rapidly expanding community of cats had driven it to extinction. By 1897, there were so many cats killing so many birds that a lighthouse keeper urged the authorities “to employ some means to destroy them.” It took another 27 years, but the successful effort to eradicate the cats was the chief reason such an abundance of seabirds survived to greet Holly Jones that night on Stephens Island.
What happened there is now standard conservation practice around the world to protect the incredible diversity of species on islands. Jones, an assistant professor at Northern Illinois University, is the lead author on a study published Monday in the Proceedings of the National Academy of Sciences that looks at the long-term effects of eradicating cats, rats, goats, pigs, and other invasive mammals from islands. On the 181 islands where biologists have conducted follow-up studies, Jones and her coauthors found that eradication turns out to be
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