Anacapa Island thrives after rat eradication

ANACAPA ISLAND — Just as factories brag about their accident-free days, Channel Islands National Park is showing off this rugged island’s rat-free decade.

To get rid of Rattus rattus, officials had a helicopter shower one-square-mile of Anacapa with poisonous green pellets in 2001 and 2002. On Wednesday, they ferried a boatload of reporters and scientists to the square-mile chain of three islets and declared victory.

“The last thing we needed was a project that got only 99.9% of all the island’s rats,” said Kate Faulkner, a National Park Service biologist.

PHOTOS: Birds return to Anacapa

Faulkner was one of the park officials on hand to demonstrate the island’s rebound since the controversial extermination program. A lawsuit from the Fund for Animals called the poison drop “an ecological disaster.” It was dismissed. A protester was arrested for allegedly seeding the island with vitamins that he claimed were rat poison antidotes. He was acquitted.

As Faulkner stopped to talk at a spectacular outlook above Cathedral Cove, sea lions basked on the beach far below. The sun was shining, the blooms of the giant yellow coreopsis were blazing, hordes of sea gulls were looking for places to mate and there wasn’t a rat in sight. More significantly, the rare birds victimized by rats were, according to biologists, thriving.

Scripps’s murrelet — a robin-sized bird that nests largely on Anacapa and Santa Barbara islands — had been on the way to possible extinction, scientists say. Rats mauling the birds and eating their eggs littered the island’s sea caves with torn eggshells. Radar aimed at the birds confirmed that something bad was going on: They were spending a week on their nests, instead of the month required for hatching, before flying off.

Now the murrelets’ nests have quadrupled. Once again, mothers force their chicks out after just a few days to skitter down cliffs hundreds of feet high and crash in the ocean. Cassin’s auklets have been seen on the island as well. For the first time, an ashy storm-petrel was spotted thanks to one of about 30 strategically placed recorders that picked up its cry and transmitted it to ornithologists at UC Santa Cruz.

The program cost about $3 million, with much of the funding coming from the American Trader Trustee Council, a conservation group that oversees a settlement from a 1990 oil spill off Huntington Beach.

Just when the rats arrived is a subject of debate. It could have been in 1854, when the paddle wheel steamer Winfield Scott was wrecked in a storm. Or it could have been decades later, when government crews built a lighthouse on a wind-swept point. What’s not in dispute, according to the Park Service, is that they were noted as long ago as 1907 and now they are gone.

As one bit of proof, they point to the mice.

Deer mice, Anacapa’s only native mammal, are bouncing back. The rats had been eating them as well.

The Park Service and its contractor, a Santa Cruz group called Island Conservation, rounded up quite a few deer mice, segregated them by sex, and caged them in an old fuel storage building dubbed “the mouse house.” Because of the possibility the mice carried hantavirus, workers dealing with them had to wear respirators and other protective gear. After the drop, they were let out again.

“There were all sort of complexities,” said Gregg Howald, an official with Island Conservation. “This was the first time anything like this had even been attempted in North America.”

steve.chawkins@latimes.com