SAN FRANCISCO (KPIX) — The US Fish and Wildlife Department is floating a controversial plan to dump one and a half tons of poison pellets on the Farallon Islands National Wildlife Refuge to get rid of an infestation of mice.

The Farallon Islands are an essential breeding ground for all kinds of seabirds including the ashy storm petrel. Half of the world’s population of that rare bird come from here. But during the Gold Rush, sailors accidentally introduced mice to the islands and now, at times, the place is teeming with them.

“You can see the grass move with the mice,” said Fish and Wildlife spokesman Doug Cordell. “That’s how many there are out there. So it’s plague-like infestation.”

The department says about six burrowing owls have migrated to the island to eat the mice and when the mouse population dies down in the winter, the owls feed on the petrel chicks. So to discourage the owls, officials are proposing dropping 3,000 pounds of poison pellets on the islands to eradicate the mice.

“Because that’s the only method that’s been proven in the field to do 100 percent eradication,” Cordell said. “You have to get rid of every single mouse, because if you don’t the population comes back.”

But if the plan seems like a strange way to protect nature, the folks at Wildcare wildlife hospital in San Rafael would agree. Communications Director Alison Hermance says their research on poisoned animals helped get the proposed product, Brodifacoum, banned for public sale in California.

“For six to eight burrowing owls, it just seems like overkill to dump multiple metric tons of bait containing an incredibly toxic, an incredibly persistent, and an incredibly dangerous toxic poison all over a National Marine Sanctuary,” she said.

They say a bird that eats one of the poisoned mice will also be poisoned, including the burrowing owls and Western gulls.  Fish and Wildlife’s own website acknowledges this but says they plan to capture the owls and haze the gulls away during the three weeks of treatment. But Hermance says that won’t be so easy.

“Western gulls are the birds that swoop down and pick French fries out of your hand,” she said. “These are not birds that are easily intimidated.”

Cordell admits that some birds could die in the operation, but it will be a trade-off to rid the island of mice and protect a species that they say is declining in numbers.

“What can we do to restore this ecosystem?” he said. “That’s all we’re concerned with and we’re not going to do anything that causes more risk than benefit to the ecosystem.”

But Richard Charter, senior fellow with The Ocean Foundation says killing birds to save birds is not an appropriate strategy.

“The term is bi-kill, accidental mortality or sickening of non-target wildlife,” Charter said. “It sounds very strange but that’s what they’re saying we need to accept. I don’t think we’re in the mood to accept it.”

Fish and Wildlife says using poisoned bait has been used successfully around the world to eliminate rodents.  Opponents say there has got to be a better way.