Biologists hope to kill all of Rat Island's rats
Just one tiny misstep, one goof, and years of planning a $3 million wildlife project will be worthless. Last week, a crew of 18 left Homer aboard the crabber Reliance, bound for little Rat Island at the end of the Aleutian chain on a mission of devastation.
By coating the island with tiny toxic pellets in an operation that begins this week, scientists hope to exterminate Norway rats, which jumped off a shipwrecked Japanese ship in the 18th century and colonized the 6,871-acre island 1,700 miles from Anchorage.
"We're planning for success," said Steve Ebbert, the biologist and invasive species project leader at the Alaska Maritime National Wildlife Refuge who's coordinating the rat attack. "Weather is a big risk. We need a string of good days."
Rats have been removed from some 300 islands around the world, including islands in New Zealand and atolls near Hawaii. But it will be the first time rats have been removed from an Alaska island - if Ebbert and his team succeed.
Rat Island is one of the 2,400 islands in the sprawling refuge that stretches from Cape Lisburne on the Chukchi Sea to the tip of the Aleutian Islands in the west and Forrester Island in the southern Alaska Panhandle region in the east.
Rats inhabit about a dozen large islands in the refuge as well as many smaller ones, feasting on seabirds and their eggs. Such seabirds as puffins, auklets and storm petrels nest on the ground, often in cracks and crevices in the volcanic rock, and the foraging birds spend considerable time away from their eggs and vulnerable young.
And the rats are nothing if not prolific.
One mating pair typically has four to six litters a year with six to 12 young in each. Hence the need to kill every last one, Ebbert said.
Although refuge managers have removed arctic foxes - another nonnative species - from more than 40 of Aleutian islands since the 1940s, this will be their first attempt at large-scale rat removal there.
"It's our mandate as a refuge to conserve, protect and enhance seabird habitat," Ebbert said. "Rats have occupied (Rat Island) for 200 years - there's no place there inaccessible to rats."
Eliminating them is no small job.
Eighteen people will stay on the island up to 45 days, until Nov. 15. Among them are four helicopter pilots flying two copters, a mechanic and a medic. The copters will hopscotch their way from Anchorage, using four fuel stops en route.
The refuge's research vessel, the M/V Tiglax, will arrive by Oct. 1 to help with logistics.
The intent is for the helicopters, slinging buckets with 700 pounds of Rodenticide pellets, to spread the powerful toxin over the entire island twice.
"We want to do it twice with a seven-day period in between," Ebbert said. But if inclement weather hampers flying, "we want to make sure we get all of the island once."
The pellets are smaller than dog-food chunks, Ebbert said, each containing anticoagulant that makes the rats bleed to death.
The helicopters will use GPS to navigate straight lines. The GPS connects to a switch that opens the buckets carrying rat poison, dispensing it every few meters.
Afterward, biologists will remove a camera card from the GPS, plug it into a computer and print out a map of the area covered.
Everyone knows they must be perfect.
"To put it in its simplest form," said Steve Mclean, Bering Sea program manager of the Alaska Nature Conservancy in Anchorage, "a single breeding pair left alive is essentially a failure."
The Nature Conservancy has raised more than $2 million toward the project, Mclean said.
"We've done the best job in the world planning," he said. "And we've worked in challenging and remote areas before."
Timing is critical. Most of the few birds left on the island are gone by late fall. Winter would be ideal, but scientists are trying to balance that against when they can safely move people and equipment to the remote wind-and-rain-battered island.
Ebbert said scientists will return in two years to check if all the rats died.
If successful, Rat Island would become the third largest island to rid itself rats. The largest was the 27,922-acre Campbell Island south of New Zealand, and two of the helicopter pilots working Rat Island are New Zealand veterans. Since the eradication seven years ago, seabirds have returned and the Campbell Island Teal, one of the world's rarest ducks, has been reintroduced.
Worldwide, rats cause up to 60 percent of seabird extinctions, with most of those happening on islands, according to Island Conservation, a California-based conservation group focused on protecting island life.
"Rats are one of the worst invasive species around," said Gregg Howald, program manager for the group, which is working with the U.S. Fish and Wildlife Service and the Nature Conservancy. "If you go to Rat Island, one thing you will notice is that it is eerily quiet compared to the other Aleutian Islands that are literally brimming with life."
The risk of rat invasions is growing.
Thousands of ships - many with rats aboard - pass through the remote, stormy archipelago each year, transiting the Great Circle shipping route between Asian and U.S. ports. Traffic through Unimak Pass, a 28-mile-long corridor through the Aleutian chain, is roughly double the amount of vessel traffic to all Alaska ports combined, according to a 185-page report published by the Washington, D.C.-based Transportation Research Board, an arm of the National Research Council.
If the Rat Island operation succeeds, will a name change be forthcoming?
Not necessarily, said Ebbert, who pointed out that any name change must go through the U.S. Board on Geographic Names that is part of the U.S. Geological Survey. Many Alaska locations "have names that no longer work," he said, such as Green Timbers in Homer, an area that holds about an acre of dead spruce, trees that died following the 1964 earthquake.
But Mclean disagrees.
"We'd like to rename it," he said. "It probably had an Aleut name at some point. Once we remove the rats and that legacy, renaming it seems like the right thing to do."
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