Over the last 3 1/2 years, Frank H. Ugolini has spent perhaps 150 nights stalking rats on East Anacapa Island, a rocky, wind-swept speck in Channel Islands National Park.
On about 15,000 occasions, he has gingerly placed raisins, macadamia nuts and, most often, dollops of NuMade Soft 'n' Creamy peanut butter in industrial-sized traps known as Victor M-9s. He has set the traps in gullies and in crevices, on the edges of cliffs and in the soft dirt beneath clumps of sage and island buckwheat.
Ugolini, the park's resource management chief, has never left empty-handed. The rat community is many hundreds of times larger than 90-acre East Anacapa's human community, which consists of a lone park ranger and some occasional helpers.
In fact, the rats, which apparently swam to the island from shipwrecks as recently as 50 or 100 years ago, have so thoroughly infested East Anacapa that they have driven out the native white-footed deer mouse--the only mammal, and one of just five vertebrates indigenous to the island.
An effort to reintroduce the mice has pitted the National Park Service, which tries to restore land under its control to a pristine condition, against the hearty Rattus rattus, which could care less about pristine. Rats arrived in North America around 1750 and have skittered around the Channel Islands for as long as a century, but, by Park Service standards, they are just off the boat.
"There's no ecosystem in the world quite like the one we have here, and I don't see any way the rat can be viewed as a natural part of it," says Charles Drost, a park biologist. "They're just such an overpowering force on East Anacapa. I think they've got to go."
The contest between man and rat on East Anacapa typifies a predicament with which the Park Service grapples throughout its 79-million-acre territory. Exotic species, which park officials view as living things introduced to an area after the arrival of the white man in North America, have made destructive inroads in more than 150 parks and monuments, jeopardizing native plants and animals. As a result, 42 native mammal populations have been wiped out at 14 national parks in the West, according to a University of Michigan study.
In the Channel Islands alone, officials worry about many animals that took to the wilds after farmers and ranchers left the islands. Pigs on Santa Rosa Island devour the roots of oaks found nowhere else in the world. Thousands of wild sheep on Santa Cruz Island decimated grasslands until recently, when the Nature Conservancy, which manages much of the island, shot them. On San Miguel Island, a pair of burros abandoned by a movie crew decades ago have spawned a herd of about 75.
Worried About Rats
Eventually, Ugolini says, the Park Service will be forced to hunt or to allow the hunting of the burros and the pigs and the other exotic species in its jurisdiction. But his most immediate worry is the rats, which, for unknown reasons, are far more voracious on East Anacapa than on the other islands.
"There hasn't been a mouse seen here since 1979," says Ugolini, "and God only knows what they're doing to the invertebrates."
Besides doing in the deer mice, with which they coexist on other islands, rats also are suspected of dining on a rare species of land snail. They can terrorize young sea birds and rampage through delicate tidal pools.
A Park Service document calls the rats "an unsettling presence" on East Anacapa, the closest of the Channel Islands to the mainland and the most frequently visited. They have chewed through new wiring in the ranger's house and gnawed doors and carpet in the island's visitor center. They have barged into campers' tents. One Park Service worker quit after he was awakened by a rat leaping onto his chest.
"If we didn't do anything, they'd probably just take over this whole island," Ugolini says. "In another 100 years, we could probably wind up with nothing but rats here."
So Ugolini, a veteran of 30 years in the Park Service, leaves his wife, son, and 82-year-old mother-in-law in their Ojai home four or five nights each month to stem the gray tide.
It is a frustrating task. Rattus rattus breeds every 22 days. Birds devour them from time to time, but members of the species survived a nuclear blast at a test site in the Marshall Islands in 1952.
Unbowed, Ugolini sets out from the East Anacapa ranger station with a basket full of traps just before dusk. He can point out empty snail shells at the mouth of rat burrows, and he knows all the gullies and culverts most frequented by rats on their nightly expeditions for grubs, roots, lizards and other edibles.
"We always get lots of action in the culverts," he says.