Mouse menace on Alaska’s St-George Island

Mice, an invasive species on St. George Island, had burrowed nests into coiled straw construction wattles and cached seed everywhere in the shipping container. After inspection, the eradication crew sent all of the material to burn barrels. (Marc Romano / USFWS)
Mice, an invasive species on St. George Island, had burrowed nests into coiled straw construction wattles and cached seed everywhere in the shipping container. After inspection, the eradication crew sent all of the material to burn barrels. (Marc Romano / USFWS)
If house mice invade your remote Bering Sea island for the first time, who do you call?

Try the mouse slayers at the U.S. Fish and Wildlife Service, the agency in charge of protecting more than 2 million seabirds near St. George Island and the nearby portion of the sprawling Alaska Maritime National Wildlife Refuge.

In what was dubbed a “rapid response” effort, two of the agency’s trappers flew to St. George in March and killed about three dozen mice found in a container van that contained parts for a power project. The cargo van had been shipped to the island’s namesake village some 800 miles southwest of Anchorge last fall. It sat in the harbor through winter.

When local work crews looked in the container van in February, lots of brown mice scurried inside.

“Let’s get some traps and be done with it,” said Chris Merculief, the tribal president, after he saw about 20 mice among the straw and metal parts.

Endangering fragile ecosystems

Invasive rodents are a serious issue in Alaska, where state law prohibits their transport and wildlife managers are ever-fearful of “biosecurity threats” that might upend fragile ecosystems, said Marc Romano, a wildlife biologist for the refuge.

“It can be looked at from the outside as maybe a silly situation, but it’s not. It’s serious,” Romano said. “It’s against state law, but that’s not why we acted. We acted because we don’t want invasive species competing with indigenous species.”

Rodent eradication efforts have been big news in Alaska. Not long ago, U.S. Sen. Mark Begich recommended that a stateless rat-infested ship, the Bangun Perkasa, that had been caught illegally driftnetting, should be used as target practice for the U.S. Coast Guard and sunk.

“The hulk should be towed far offshore, well beyond the rats’ ability to swim, and then the Coast Guard should open fire,” Begich wrote.

In the end, marine salvage crews from Unalaska exterminated the mice and the ship was cut into scrap metal.

In another incident not long ago, the Fish and Wildlife Service dropped rodenticide from helicopters and spent $2.5 million to get rid of invasive rats that decimated seabirds on what’s now called Hawadax Island — formerly known as Rat Island — in the Aleutian Chain.

As for the house mice, they apparently arrived in Alaska on ships during the Russian era in the 18th or 19th century and have become a nuisance in many locations, including Anchorage, Romano said. But they never established themselves on St. George.

Concern for seabirds

The U.S. Fish and Wildlife Service wasn’t worried the house mice would devastate the island’s seabirds, which includes 80 percent of the world’s red-legged kittiwakes. But it could be possible. Swarming mice were caught about a decade ago scurrying atop and gnawing on a much larger albatross chick in a gruesome video taken on Gough Island in the South Atlantic, Romano said.

Until then, scientists had never documented mice feeding on seabirds, he said.

“The moral is if it can happen there to a chick the size of an albatross, it can happen anywhere to any other species,” said Romano.

Scientists were more afraid the St. George mice would get a foothold on the island and hurt the ecosystem, perhaps providing more food for foxes that eat bird eggs, or threatening the unique native population of island lemmings, about which little is known.

As soon as the mice were discovered, Sally Merculief, the St. George tribal administrator, combed her house inside and out for mouse droppings, but never found any. “I was pretty concerned,” she said. “We don’t want to get a mouse infestation on the island.”

The container van had been sent for an Alaska Energy Authority project and contained parts for wind turbines and materials for landscaping, Romano said. The mice were living in the straw bales and had cached grass seed for food.

Using some traps already on the island and more that were sent by the Fish and Wildlife, the local tribal government initially caught 17 mice in the container van.

But that wasn’t enough to stop the mice, and Fish and Wildlife took bigger steps. Plans to fumigate the mice — at $2,000 a day to hire a contractor — never materialized because the materials couldn’t be shipped on commercial flights, and no cargo-only flights were available, according to a report from Fish and Wildlife.

37 mice killed

The city of St. George offered to gas the mice using vehicle exhaust, but that wasn’t done either.

Finally, in mid-March, Fish and Wildlife sent out trappers. With help from two city employees and funding from the National Fish and Wildlife Foundation, the trappers finished the job and killed another 37 mice.

The mice apparently never left their food and hay in the container van, said Romano. A heavy equipment operator lifted the van and the trappers found no evidence of burrowing. Bait stations around the container van and harbor also showed no sign of mice.

The project cost the agency less than $5,000, expenses mostly related to travel, said Romano. The Alaska Energy Authority also helped by covering lodging expenses. “This wasn’t some $100,000 project to get 50 mice,” he said.

Residents said they’re relieved. The birds attract tourists, who spend money on St. George.

“I feel a lot better,” said Sally Merculief. “You know how they can multiply.”

Contact Alex DeMarban at or on Google+

Related Links:

Canada: ‘Exotic’ species showing up in Canada’s Arctic, CBC News

Finland:  Warm weather delays bird migrations in Finland, Yle News

Sweden: Sharp-edged mussel invades southern Sweden, Radio Sweden

United States:  What on Earth are bats doing in Alaska?, Alaska Dispatch

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