JUNEAU — Conservationists and federal wildlife officials are reporting success, five years after undertaking an effort to eradicate rats from a remote Alaska island.
Officials with Island Conservation, The Nature Conservancy and U.S. Fish and Wildlife Service said Wednesday that the island — once known as Rat Island because of its infestation of invasive Norway rats — is now teeming with birds, whose songs and noises have replaced the silence that had been reported there when the rats ran rampant.
They said for the first time, breeding tufted puffins have been documented on the island, which is part of the Alaska Maritime National Wildlife Refuge and near the far end of the Aleutian Island chain that stretches out into the Bering Sea. They also reported an increase in ground-nesting and shorebird numbers compared to prior surveys and documented song sparrows, which were not recorded during prior visits, said biologist Stacey Buckelew, who worked as a contractor for Island Conservation earlier this year when the latest survey was conducted.
The makeover of the island includes a name change: Rat Island officially became Hawadax Island, a nod to the original Aleut name, in 2012.
Randy Hagenstein, Alaska state director for The Nature Conservancy, called the transformation “one of the successes for conserving island ecosystems around the world.”
“We set the island back on its course to being a normal, productive and noisy island full of bird life,” he said.
Buckelew said islands infested by rats are “void of wildlife, more or less,” with the rats basically eating themselves out of house and home. What one finds instead are rat scat-covered rocks, remains of snails and other creatures, scavenged bird bones and “this eerie silence,” said Buckelew, who had done prior work on islands in Mexico affected by rats and other invasive species.
The Aleutians are tree-free, she said, with the highest vegetation being coastal grass. Rats were able to get into burrows used by birds for nesting and eat eggs and chicks, she said.
The rats were eliminated through the use of poisonous bait pellets.
Now that the rats are gone, “what’s beginning to happen is, you’re getting a recovery of this rich and vibrant community that you see on other islands in the Aleutians,” she said, declaring the island “hardly recognizable.”
“The features are the same, but you hear birds that weren’t there before the eradication,” she said.
Rats are believed to have gotten their start on the island in the 1780s with a shipwreck. Buckelew estimated there were 10,000 or more on the roughly 6,800-acre island when eradication efforts began in 2008. Their reproduction rate was prodigious with a female capable of producing a litter of up to 12 young every three to six weeks, she said. Had a single pregnant female been left behind, that would have been enough to repopulate the island again, she said.
While the island is uninhabited by humans and visited by few, part of the value it provides to people is the knowledge that there are places like this set aside for wildlife, refuge manager Steve Delehanty said. It also provides shelter for birds, some of which are migratory, he said.