VANCOUVER -- Scientists at the Vancouver Aquarium have sprung into action, as part of an effort to prevent an endangered frog population from becoming extinct in eastern British Columbia.
The Rocky Mountain population of northern leopard frogs plummeted by the millions in the 1970s, and only two populations are now known to exist near Creston, in B.C.'s West Kootenay region.
The aquarium announced Thursday its scientists have, for the first time in Canada, bred the species in an aquarium setting and created an assurance -- or backup -- population.
Dennis Thoney, the aquarium's director of animal operations, said officials plan to release about 2,000 tadpoles Monday in the Columbia Marshes near the east Kootenay city of Cranbrook, while maintaining a population at the aquarium.
He said the frogs are expected to become the third Rocky Mountain population of northern leopard frogs in the province.
"Frogs, in general, are facing probably the largest extinction since the dinosaurs right now," said Thoney. "Of the 6,000 species, a third to more are threatened or endangered now."
Known by the scientific name Lithobates pipiens, the species is medium sized, green-brown in colour and possesses distinctive dark spots encircled by paler rings that resemble halos.
The frogs possess large hind legs with dark bars and are known for their pale under parts.
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(Vancouver Aquarium photo) |
From nose to rump, the frogs measure between 5.5 and 10 centimetres, and have a distinctive call described as a "chuckling" or "gabbling" or even as a hand rubbing against a wet balloon.
Scientists don't know why the population plummeted.
Suspected causes for the decline include habitat destruction, water-quality changes, the introduction of new species like the bull frog, and the spread of a fungus carried by the African clawed frog, which at one time was injected with urine from human females as part of pregnancy testing, said Thoney.