COLUMN ONE : A Deadly Plague of Stowaways : Carried by ships to islands around the world, rats have wiped out millions of birds. The U.S., other countries have done little to counter this threat to global ecology.

Somewhere on the oceans of the world a weather-beaten fishing trawler is about to dock at a tiny island. Tonight, tomorrow--but surely someday soon--a leaky grain barge is headed aground on a far-off atoll.

And so will commence another maritime disaster destined to inflict greater punishment on the world’s wildlife than the Exxon Valdez oil spill.

Only no one will clean up this mess, probably ever. And judging by history, no news reporters and cameras will rush to the scene.

Rather than the 400,000 birds that died in Exxon’s crude oil, the worst spill in U.S. history, this hypothetical disaster may kill 4 million birds or more and prevent their return forever.

The rats are coming.

Stowed away in the lockers of the trawler might be a pair of one-pound Norway rats ready to scoot down a hawser after sunset dragging their naked tails behind them to a new homestead; deep in the hold of the grain barge are a family of evil-eyed Polynesian rats about to ride the surf onto a lush beachhead.

We know this will happen because it’s been happening for generations--at the rate of six or seven island invasions a year every year since 1841, by one count. And the world’s birds are paying a horrible price.

Here at the gateway to the great arc of the Aleutian Islands, south down the Pacific coast offshore of California, in the Indian Ocean, off the coast of New Zealand--anyplace where there are islands, nesting birds have been, and remain, sitting ducks.

Through commerce and fishing, exploration and military maneuvers, we have spread rats to 82% of the world’s islands, according to federal scientists. Rats prey on birds in several ways, with eggs and chicks particularly vulnerable. Scientists said rats bring down larger birds by biting the backs of their necks, severing their spines or sometimes, gruesomely, chewing off their legs.

In the last few centuries these rodents have wiped out millions of island-nesting birds and other creatures, driven a significant number to extinction, transmitted disease to other species and dug in against everything we can put up against them.

For all that, however, America and many other coastal nations have prepared virtually no island defenses against tomorrow’s invasion by rats.

The U.S. Fish and Wildlife Service recently sent a letter to fishing and shipping companies and island residents seeking cooperation in rat control. But officials concede that is only a modest effort, and blame budget constraints and a lack of foresight by policy-makers for preventing a serious approach.

The state of Alaska, for instance, which is home to North America’s richest sea bird nesting grounds, has a budget of $5 million for oil spill prevention. Cleanup of the 1989 Exxon spill cost more than $2 billion.

The federal officials charged with rat control, by comparison, have an $8,000 annual budget for Alaska. The only weapon that has shown any success--poison--is denied them by federal pesticide regulations. And they are worried sick that two pristine, bird-rich islands in the Pribilof chain in the Bering Sea might be under rat invasion right now.

If one adds cats, foxes and mongooses to the mix of predators that people introduced to islands, the recorded devastation to wildlife is truly dire.

“There were battles of World War II fought in the Aleutian Islands, they tested nuclear devices there, we’ve had oil spills and toxic chemical releases all over the place. And none of these things have done anything remotely compared to the destruction of native animals by rats and other introduced species,” says Vernon Byrd, supervising wildlife biologist for the vast Alaska Maritime National Wildlife Refuge. The refuge encompasses 3,000 islands.

A global sampler of the problem:

* In Channel Islands National Park off Ventura County, roof rats--the third of the three damaging varieties--have been established for decades on Anacapa Island. An eradication effort in the 1980s failed. Park officials say birds that colonize other islands are not found on Anacapa, but they don’t know if rats are to blame. Further south off Baja, the Guadalupe petrel went extinct about the same time that rats were thought to have landed on the island.

* In the southern Indian Ocean, rats and feral house cats annually kill an estimated 450,000 burrowing petrels on just one island--Marion Island--and another 1.3 million birds of different varieties in the Kerguelen Archipelago.

* According to a 1992 scientific study by Australian and New Zealand ornithologists, 93% of the terrestrial and fresh water birds that have become extinct in the last 400 years were on oceanic islands. And of these, 70% were caused by rats. Island colonies of snakes, ginkos, frogs and other creatures also have been driven to extinction.

* Just south of the Alaska state line in British Columbia, Langara Island lost four species of birds that numbered 50,000 to 100,000 20 years ago. This because of a shipwreck that established rats on the island.

* Rats are so tenacious, hardy and adaptable, the largest island where they have been eradicated is less than one mile square, located off the coast of New Zealand. So amazing was the achievement, a movie was made of the struggle, called the Battle of Breaksea. New Zealand is acknowledged to have the most aggressive program of any nation for repelling invading rats, relying on immediate application of poison.

* On 13-acre Rose Atoll in American Samoa rats ranged freely since at least the 1920s, destroying birds, young turtles and succulent plants. Biologists described a scene in which a blanket of rats covered beaches at night, picking it clean of all animal remnants save bird beaks. In a 40-day campaign of trapping and poisoning in 1990, U.S. officials hope they have eradicated the rodents. Already birds are beginning to re-establish themselves.

“Everyone is focused on oil, oil, oil--but these are threats that are far worse,” says U.S. Fish and Wildlife Service Biologist Edgar Bailey.

This spring, Bailey prepared an emergency rat response proposal for federal officials in Alaska. He cited three ship groundings near the Aleutians in recent years, including one Korean grain ship that foundered in the vicinity of islands where there are colonies of from 50,000 to 250,000 birds. Scientists do not know if rats made it ashore.

The Aleutians are the long archipelago that extends south and west from the Alaskan mainland like an elephant’s trunk. Birds use these northern islands only seasonally for nesting, but both foxes and rats use them for year-round food, building caches of bird carcasses for winter. Among the abundant birds of the region are murres, auklets, puffins, petrels, terns, murrelets and gulls.

Bailey said agency superiors rejected his response plan, partly because he called for the standby use of poisons to try to stop invading rats before they get established. Use of these powerful toxins is not permitted on federal refuge lands. Changing those rules would be costly.

Of course, Bailey argues that being unprepared will prove much more costly.

“In New Zealand, if there is an accident near an island, they lace the beach with poison as soon as weather permits. They fumigate the ground. Whereas we have no plan. It scares me to death,” says Bailey.

On a map, he points here and there to the truly colossal Alaska bird colonies that remain untouched--and therefore vulnerable. “There are so few, you can count these practically on your fingers,” Bailey worries.

One of them is tiny Buldir Island, near the western end of the Aleutians. Forty miles from other land, Buldir is home to the most diverse and largest sea bird colony in North America, some 4 million birds. It also happens to be adjacent to the Great Circle shipping route in a region renowned for fog and raging storms.

“We have no contingency plan if a ship or a grain barge goes around there,” Bailey says.

Of more urgent concern are the Pribilof Islands, north of the Aleutians in the Bering Sea. Homesteaders have recently built ports on the two main islands in this remote chain--home to 2.75 million birds and 900,000 fur seals. In additional to preying on birds, it is possible that rats could spread disease among the seals.

Federal officials have tried to educate local residents on the dangers of rats. But conditions are thought to be very inviting for an invasion--growing volumes of ship and barge traffic and ready sources of food.

The chances of keeping rats off both of the main Pribilof Islands are “a long shot,” says wildlife service biologist Arthur L. Sowls, who is in charge of the government’s prevention campaign.

Some of Alaska’s leading environmentalists have joined government officials in trying to sound the alarm and face up to the problem, rather than wait and react when it happens.

“It bothers me personally how we set our priorities,” says the Sierra Club’s Pamela Brodie, one of Alaska’s foremost environmentalist experts on the Exxon Valdez spill. “We tend to ignore the chronic problems--which can be much more serious--in favor of the occasional accidents.”

Times researcher Doug Conner in Seattle assisted with this story.

A Small but Fierce Predator

Because of their ability to live near humans, Norway and roof rats are two of the types responsible for much of the damage to birds and habitat. They are aggressive, adaptable and will eat almost anything. They can produce up to seven litters a year, each containing six to 22 young.

NORWAY OR BROWN RAT

* Size: Head and body 7 to 10 inches

* Description: Tail is shorter than the body. Short ears, underparts usually grayish, sometimes white. Norway rats are more common in North America than roof rats.

* Habitat: Homes, farmyards

BLACK OR ROOF RAT

* Size: Head and body 7 to 9 inches.

* Description: Smaller than Norway rat but with longer tail. Black on top, white to slate-color underneath. Tail is longer than body. This rat is associated with “black death” or bubonic plague.

* Habitat: Ships, trees, homes

Sources: Encyclopedia Americana, Encyclopedia Britannica, World Book Encyclopedia, Harper & Row’s Complete Field Guide to North American Wildlife.