Quebec aquariums and zoos are leaping to the defence of an animal that is increasingly threatened with extinction in La Belle Province and around the world — frogs.

The Quebec croaker and its amphibious friends are disappearing at a massive rate, with scientists estimating that up to one-half of species worldwide are in danger of disappearing. Some 120 species of amphibians have become extinct in recent years, scientists say.

"It's not later, it's now," said Caroline Bourque, assistant director of the Ecomuseum in Ste-Anne-de-Bellevue, near Montreal.

"And it's not just in Quebec, but in Canada and around the world. Biologists are shouting out that it's very important."

This leap year has been designated Year of the Frog by worldwide conservation groups. Six Quebec zoos and aquariums are joining others around the world in marking the year's official launch on Feb. 29.

In Quebec, one species — the western chorus frog — is on a threatened list, while five others among the province's 20 species of amphibians are headed toward the same fate.

The chorus frog's main habitat in the grassy wetlands in the St. Lawrence River valley are drying up in a swirl of development.

David Rodrigue, co-ordinator of the Quebec amphibian-monitoring program, said 25 per cent of the frog's 800 breeding sites in the valley were filled for development in one year between 2006 and 2007.

"It's incredible," said Rodrigue, who is also executive director of the Ecomuseum. "Honestly, if it keeps going the way it's going, in 15 or 20 years [the chorus frog] will be gone from Quebec. And there are a number of species facing the same fate throughout Canada."

The American bullfrog, found on Canada's East Coast, and the coastal tailed frog are among the threatened amphibians in Canada. But British Columbia's Oregon spotted frog is among the most vulnerable, with only two known habitats remaining in the province.

"People might think, `Frogs, ah, frogs, why is that important?'," said Julie Séguin, director of conservation at the Granby Zoo near Montreal.

"If you want one less mosquito at your summer picnic, frogs are important because their diet of insects is just one way they help humans."

Most scientists believe global warming is contributing to amphibian decline, but an epidemic of infection by a fungus called chytrid is decimating populations, particularly in the south.

Few amphibian populations survive an infection, Rodrigue said, adding that some 500 amphibian species, many in warmer climes, are heading toward extinction.

"That's serious, that's a bigger mass extinction than the dinosaurs," he said.

The northern leopard frog in B.C. appears to be the only Canadian species to suffer the infection so far, but nobody is sure why it has so far survived, Séguin said.

Conservationists say frogs, with their ability to live in water and on land at different stages of life, are canaries in the environmental coal mine. Their thin skins absorb air and water and whatever toxins they may contain.

"They are extremely sensitive," said Séguin.

"They are the first to ring the alarm when something is going wrong in the environment. The amphibian decline tells us things are going badly around the world."

Rodrigue says amphibians would not be slipping toward extinction with little notice from the world at large if they were furry and cuddly creatures.

"If grizzly bears were disappearing at the same rate, it would be big news," Rodrigue said.

"And, not to put more value on one species than another, the implications for the environment of amphibian extinction are much more important."