Scottish isle eradicates rats in bid to save birds
LONDON -- The tiny Scottish isle of Canna has successfully eradicated the island's rat population after a three-year campaign to protect the island's seabirds from the rodents, environmental officials said Saturday.
The island's soaring cliffs are ideal nesting grounds and host about 15,000 seabirds from 14 different species, according to the National Trust for Scotland, which manages Canna.
But the birds found themselves under threat when brown rats, accidentally introduced to the island hundreds of years ago, began appearing in greater and greater numbers, something the trust said was probably due to warmer winters.
The rats were devouring the birds' eggs, killing their chicks and devastating many of their colonies. Some birds, like the long-winged Manx Shearwater, were almost driven from the island entirely.
In 2005, the trust brought in a team of pest-eradication experts from New Zealand. Working with volunteers, they laid 4,388 traps out in a carefully plotted grid across the five-mile-long island, rappelling down the sides of cliffs to reach the more inaccessible areas.
Some 25 tons of rodenticide were shipped in to arm the traps, and by early 2006 the island's estimated 10,000-strong rat population had largely disappeared.
Authorities and volunteers have since been monitoring the island by leaving chocolate-flavored wax around Canna and keeping an eye out for the rats' distinctive nibble marks. With no confirmed rat sightings in more than two years, the British Environment Minister Mike Russell declared the island "officially rat-free."
Canna, more than 25 miles off Scotland's western coast, is home to about a dozen people.
