Island Has Dead Birds, No Rats
An Animal Rights Article from


Mike Campbell on
July 2009

The first check on the effects of a $3 million rat-poisoning campaign on remote Rat Island turned up no living rodents on the 10-square-mile island in the Alaska Maritime National Wildlife Refuge -- but 227 dead birds.

Nine months after blanketing the island with compressed-grain pellets of Rodenticide, a seven-member survey team this week collected 186 glaucous-winged gull and 41 bald eagle carcasses. Most were juveniles, many in advanced stages of decomposition.

"Certainly, the numbers are far higher than we would have anticipated," said spokesman Bruce Woods of the U.S. Fish and Wildlife Service. "It's not clear why. We'll have to wait for the lab results."

Woods said it's unlikely carnivorous eagles ate the Rodenticide grain pellets, but they may have devoured some dead rats that had consumed them.

"Eagles are scavengers of opportunity," he said. "Rats don't make up a big part of their diet naturally, but if meat is available, they're going to take it."

An assessment conducted before the pellets were dropped on Rat Island suggested birds would have to consume a large number of rodents to be harmed by the poison.

Bird carcasses and tissue samples have been sent to the National Wildlife Health Center laboratory in Madison, Wis., to determine the cause of death. Results are expected later this month.

Nearly two dozen people -- some in helicopters -- participated in the eradication project last September on the Aleutian island some 1,700 miles from Anchorage.

They coated the island with toxic pellets, hoping to exterminate Norway rats, which jumped off a wrecked Japanese ship in the 18th century and colonized the 6,871-acre outcropping. The island is one of more than 2,400 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 have been removed from some 300 islands around the world, including islands in New Zealand and atolls near Hawaii. This was the first attempt to remove rats from an Alaskan island.

All together, 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.

Prolific rats can produce four to six litters a year with six to 12 young in each -- making complete eradication necessary.

"To put it in its simplest form, a single breeding pair left alive is essentially a failure," Steve Mclean of the Alaska Nature Conservancy in Anchorage said as the project got under way last year.

The Nature Conservancy raised more than $2 million for the project, Mclean said.

"So far, no living rats have been observed," said Woods, who noted that seven observers walked the island looking for signs of survivors. "We're cautiously optimistic, but it's a big island. It would be presumptuous to assume that we would have noticed rats if only a few were left."

Before federal biologists consider the island rat-free, they will survey it again next year.

"We are extremely pleased with no rats in evidence on the island," said Bill Waldman, executive director of Island Conservation, another organization that was a partner on the project. "We're surprised and concerned with the mortality."

Fish and Wildlife said none of the bird deaths happened recently, and pointed out the losses "will not significantly impact" overall Aleutian bird populations. The agency estimates some 2,500 eagles live in the Aleutians, with gull numbers far higher.

Woods said researchers did a small test application on an island near Adak before the Rat Island project and did not note any eagle deaths.

This week, field workers collected additional tissue samples before destroying bird carcasses to eliminate any ongoing risk.

Eagles were the only area bird species not to see a population increase since the rat poison was applied last September, according to the fish and wildlife service. Juvenile eagle numbers, in particular, were lower.

Black oystercatchers were found on the island for the first time, Woods said. Aleutian cackling geese, ptarmigan and peregrine falcons are also there.

"We're already seeing species nesting out there that are very vulnerable to rats, and that's a very encouraging sign," said Randy Hagenstein of The Nature Conservancy. "Nobody likes to see dead birds, but we're trying to not jump to any conclusions.

"We want to get to the bottom of it. We need to know exactly what went on. But the bottom line is that Rat Island is now going to produce generation after generation of eagles, oystercatchers and other birds."

To kill the rats, helicopters emptied buckets filled with 700 pounds of toxic Rodenticide pellets over the island last year. The pellets, smaller than dog-food chunks, containing an anticoagulant that, when consumed, makes the rats bleed to death.

The Rat Island Restoration Project is a partnership among the U.S. Fish and Wildlife Service, the Nature Conservancy and Island Conservation. The project was reviewed by the Alaska Department of Environmental Conservation, the U.S. Fish and Wildlife Service, the Environmental Protection Agency, and National Marine Fisheries Service.

If the project is successful, Rat Island will become the third largest island to rid itself of rats. The largest is 27,922-acre Campbell Island south of New Zealand.

Worldwide, rats cause up to 60 percent of seabird extinctions, with most of those happening on islands, according to Island Conservation, the California-based conservation group that's focused on protecting island life.

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