Next week, Vancouver Aquarium Marine Science Centre will be releasing 500 tadpoles of the endangered B.C. Northern leopard frogs into the wild after a fourth successful breeding season.
The tadpoles, which hatched in the last week, will be released into the wild by the Northern Leopard Frog Recovery Team in the Columbia Marshes near Cranbrook, B.C. Since the program began in 2013, the Vancouver Aquarium’s frog propagation program has introduced more the 5,000 tadpoles to this particular site.
However, over the last two years the number of tadpoles produced has decreased — due in part to warmer weather during the winters. “Typically, when frogs come out of hibernation their bodies send a signal that it’s time to begin breeding. However, with the warmer temperatures we’ve experienced, that process is slower to start or not happening at all — resulting in a lower number of tadpoles being produced,” says Kris Rossing, senior biologist at the Vancouver Aquarium.
Despite lower numbers, releasing 500 tadpoles is still a key step on the road to recovery for the Northern leopard frog in the wild. Frogs are indicators of overall environmental health and play an integral role in their ecosystems. “The Vancouver Aquarium is dedicated to conserving aquatic life and many amphibian populations, facing a perilous future, are in need of protection,” added Rossing.
The Vancouver Aquarium, as part of the B.C. Northern Leopard Frog Recovery Team, was the first aquarium to breed these endangered frogs as part of an assurance population. The Aquarium is contributing to a world wide effort, along with other zoos and aquariums, to conserve this and other amphibian species like the Oregon spotted frog, under the Amphibian Ark (AArk) project.
The Northern leopard frogs in Western Canada, especially in British Columbia, are one of the most at-risk amphibian populations of the species. This population was once found at many sites in the Kootenay and Okanagan regions, but their numbers in western Canada fell to a point where only one wild population existed – in the Creston Valley. In 2004, a second population was reintroduced in the Upper Kootenay Floodplain, near Bummers Flats, as part of the recovery effort for this species. In 2013, a third population was reintroduced at the site in the Columbia Marshes, representing another small step in the recovery of the species.
Unlike the Rocky Mountain population of this species, the Prairie Northern leopard frogs have reoccupied some of their former range on the Prairies, and these populations are now listed as a species of special concern by Committee on the Status of Endangered Wildlife in Canada (COSEWIC). In eastern Canada they are classified as not being at risk.
The Northern Leopard Frog Recovery Team implements conservation actions as outlined in the Northern Leopard Frog recovery strategy.