San Francisco's Killer Frogs a Statewide Threat

Kill me, please

​A tiny pond near the mouth of Golden Gate Park is host to as many as 10,000 invasive African clawed frogs so voracious they're a threat to the entire state's rivers and bays. They've consumed the pond's other frogs and fish, and have taken to eating each other -- just as they'll do in other lakes, ponds, and streams if they ever manage to reach other waterways.

"They're cute, and small. They're very invasive, aggressive, and will eat anything they can stuff in their mouths," says Oakland animal activist Eric Mills, regarding the tiny African Clawed Frogs that infest the Lily Pond across JFK Drive from the Conservatory of Flowers.

Yet for at least six years, officials with both the city's Department of Recreation and Parks and the State Department of Fish and Game have bungled efforts to eliminate the invasive critters.

"Fish and Game says, 'We're working on it.' Bullshit. They totally screwed this one up," said retired state warden Miles Young. As patrol lieutenant overseeing San Francisco, Alameda, and Contra Costa Counties, in 2004 he assembled a group of experts to rid the frogs from the pond. But he was thwarted by Sacramento superiors. "It was all set and ready to go and they canceled it."

Frogs can be dangerous...

​The spectacle of killing thousands of frogs might have made the agency look bad, was one line of thinking. The frogs have an intimate, if forgotten place in local history. During the 1950s, the frogs were used in a popular pregnancy test whereby urine from a woman who'd missed her period was injected into the frog. If the frog ovulated, it meant the woman was pregnant. But that was then and this is now: Modern pregnancy tests have relegated the frogs to merely being invasive pests.

On July 18, Department of Recreation and Parks director of operations Denny Kern was quoted as saying the city has wanted to eradicate the frog for a decade, but hasn't had enough money. Eliminating the frogs would require sealing off the area.

The water level at the pond, which is in an old quarry and has no natural source, must be kept at a certain level or the frogs will head for waters in other parts of the park, he was cited as saying.

However, Young said this explanation isn't consistent with how the frogs operate. African clawed frogs are purely aquatic and can't survive on land.

"They migrate, sure -- in Africa when the plains flood," said Young, who assembled a crew of scientists and other experts to advise the aborted 2004 frog operation. "If they want to get rid of them, they need to drain the pond, suck them out, and be done with it."

If school children collect tadpoles or frogs from the pond as pets, then deposit them in other waterways, Northern California could end up with a much wider and destructive infestation. To keep the frogs in check, park workers every year have netted scores of them. But truly getting rid of them would involve draining the pond, digging up egg-and-tadpole infested muck, and either killing them with chemicals, or by letting them dry out.

"They could have done this for a fifth of the cost they do every year they do seining the frogs. I watched as they wade around in the muck and frogs were zipping ahead of them. It's ridiculous," said Young. "We had a pump that would have drained the pond in three and a half hours."

Mills said he could easily raise a team of volunteers to get rid of the frogs, but he said he's unable to get permission from park officials.

"I'm writing a book on the damned thing," said Young. "About the inefficiency of the whole operation."

In San Francisco, that genre could fill a library.

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