The last cats on Ascension Island in the south Atlantic held out in the volcanic rocks around Cricket Valley, on the eastern tip of the island. They were all female: according to Mike Bell of Wildlife Management International, a New Zealand company, who was in charge of eradicating the island’s 500 or so feral cats, females tend to be shy and wary of potential traps. Mr Bell and his colleagues tried everything: fish, cat biscuits, day-old chicks, traps of all shapes and sizes. Eventually, on January 30th 2006, about six months after they had expected to finish the job, they trapped the last one—“a scruffy tabby, quite small”—and for the first time in 200 years the islands were safe for birds.
In 1815, when the island was first garrisoned by the British, around 20m birds are thought to have been living on it. By 2000, thanks largely to the offspring of ships’ cats, the numbers were down to a few hundred thousand. The rocks were covered with ghost seabird colonies—miles of stony ledges covered in guano deposited over millennia, with hardly a bird to be seen. The Ascension frigate bird, endemic to the island, had been driven to nesting on an offshore rock the cats could not get to.
Most eradications of undesirable species have been carried out on unpopulated islands, but Ascension has people—soldiers and spies, mostly, manning the British military base and listening post. Many of them had adopted cats from the feral population. Around a third of the tame cats died, which caused some contretemps between locals and eradicators.
The eradication programme may not have worked out for some of the cat owners—though since the human population is transient, the bereaved may have found feline love elsewhere—but the bird population is rebounding, and last year the Ascension frigate bird nested on the island itself for the first time in 150 years. Credit goes to the RSPB, which organised the eradication programme, and the British government, which paid for it. More....