Frog Invasion

First it was the exploding toads in Germany and Denmark. Now it's an all-out invasion of frogs in France.

A campaign in France to exterminate frogs may sound like the beginning of a civil war, but these are no ordinary frogs.

The aggressive and voracious bullfrog (Rana catesbeiana), introduced illegally 37 years ago, can grow to more than 4lbs in weight and almost 2ft long. It consumes other frogs, fish, lizards and even small birds.

Hunters working for the government's wildlife agency will be stalking ponds in south-west France this weekend, aimed with flash-lights, rifles, silencers and night-vision sights.

They have been mobilised for the most intensive effort so far to terminate a plague of giant Californian bullfrogs which is threatening to disrupt the ecology of the Gironde, Dordogne and several other départements.

I find it surprising that these frogs are said to hail from California, because I've never seen two-foot, four-pound frogs here before. I lived in a condo years ago, where there were creeks running through the complex that had frogs. If you put your thumb and index finger together to form an "O" that's as big as our frogs ever got. Most of them were a little smaller.

They came through our condo a lot, because we left the slider door open to let our two cats come in and out. Every once in a while, we'd see one of the cats focused on the floor by the wall, and we'd know a frog was there. Since one cat had proved himself a good mouser, and the other was good at catching birds, I think they were trying to decide if the frog was a mouse or a bird. Since it was neither, no frogs were ever harmed in our condo by the cats. Just in case, we'd grab the cat, put him outside, shut the slider door, and hurry the frog out the front door. Then we'd let the cat back in and he'd try to find the frog again for a while, until he decided it must be nap time.

So I can't comprehend the size and hardiness of these frogs in France. And apparently, neither can France's wildlife and fisheries groups:

Destroying the frogs is not easy, however. The Gironde fisheries protection association attacked a pond full of bullfrogs with electricity a few years ago. The frogs fought back. The hunters battled with them for two hours. They killed just one frog before they gave up.

Game-keepers and volunteers working for the Office National de la Chasse et de la Faune Sauvage (National Hunting and Wild-life Agency) have now developed night-fighting techniques. The frogs are easier to locate at night because their eyes reflect torchlight.

"Shooting them with rifles is the most effective method we have found," said an environmental campaigner, Luc Gueugneau.

Even so, experimental attacks on ponds and lakes over the past 11 months have killed only 120 frogs. A much bigger offensive, starting this weekend, aims to exterminate all the bullfrogs in France within five to 10 years.

To that I say, "Bonne chance!"