A northern leopard frog.

A northern leopard frog.

Northern leopard frog eggs highest in the Creston Valley since 1997

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The spring and summer of 2014 have been very good for endangered northern leopard frogs in the Creston Valley and East Kootenay. For a second year in a row, captive breeding at Vancouver Aquarium was successful (allowing for the second release of tadpoles in the Columbia Marshes following the first release in 2013), breeding was confirmed at two ponds at the upper Kootenay reintroduction site, and to top off the positive news, the number of northern leopard frog egg masses detected in the Creston Valley was the highest since records began in 1997.

“It has certainly been a very rewarding year for members of the northern leopard frog recovery team,” says Dr. Purnima Govindarajulu, chair of the recovery team and small mammal and herpetofauna specialist with the B.C. Ministry of Environment. “Collectively, we feel we are making significant strides forward in ensuring that the northern leopard frogs will remain part of the B.C. landscape for generations to come.”

A total of 39 egg masses were found in the Creston Valley by biologists funded by the Fish and Wildlife Compensation Program (FWCP) — almost double that of the previous record count of 22 in 2012. Finding so many egg masses bolsters the recovery effort for one of the most at-risk amphibians in the province. The reintroduction of northern leopard frogs to the East Kootenay has hinged on finding and protecting a sufficient number of egg masses in the Creston Valley.

“This year’s record-breaking find of egg masses is related to the relatively high number of egg masses in 2011 and 2012, as those eggs have turned into frogs that are now of breeding age,” says wildlife biologist Barb Houston, who manages the northern leopard frog project for the FWCP. “The population in the Creston Valley is likely increasing due to a combination of factors, including efforts to protect egg masses from predators with mesh cages, changing land management practices with the support of land owners and possibly because the frogs now have a higher resistance to the fungal disease chytridiomycosis.”

Over the last four years, about 30,000 tadpoles have been moved from the Creston Valley to Bummers Flats north of Cranbrook. Surveying, funded by Columbia Basin Trust and the Aboriginal Fund for Species at Risk through the Ktunaxa Nation, found evidence that breeding has been successful at Bummers Flats.

The high number of egg masses found in the Creston Valley has also allowed the FWCP to supply tadpoles to the Vancouver Aquarium to support their captive assurance colony. This colony is an insurance policy of sorts, where the tadpoles have been reared and bred in captivity, with the progeny used to support endangered northern leopard frog recovery efforts in the Columbia marshes.

In the 1970s, populations of northern leopard frogs across Western Canada declined sharply, especially in B.C., and the Rocky Mountain population, which is listed as endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). The species is also on the provincial red list.

“While the population remains extremely fragile in the province, the record number of egg masses found, together with the successful reintroduction results in the East Kootenay, certainly allow us some cautious optimism for the northern leopard frog,” added Govindarajulu. “We look forward to making similar progress in 2015.”