In the marshy waters of interior B.C., 400 Northern leopard frog tadpoles were released yesterday as part of ongoing conservation efforts to boost the endangered species’ wild population. Northern leopard frogs are among the most at-risk amphibian species in the world. For the past five years, Vancouver Aquarium, an Ocean Wise initiative, has successfully bred and released thousands of healthy tadpoles as part of the Northern Leopard Frog Recovery Team.
“We’re beginning to see the impact of our efforts to repopulate B.C.’s most at-risk amphibian, and have found animals that have survived the winter and are being located again year after release. There has also been evidence of breeding activity with adult males calling, all of which are indications of the program’s success to date,” said Kris Rossing, senior biologist at Vancouver Aquarium. “This long winter, however, did have an impact on some of the wild populations as well as the frogs at the Aquarium. Some were slower to breed or didn’t at all. Climate change affects the food chain from the bottom to the top, and frogs are an important indicator species of environmental health. Overall, we’ve seen our conservation efforts make a difference, as we collectively move the needle a little bit every year through this vital program.”
Yesterday, a small team travelled to the release site near Brisco, B.C., courtesy of London Air, and introduced 390 tadpoles and 10 froglets to help repopulate the vulnerable Rocky Mountain population. The day began at 6 a.m., with the tadpoles and froglets carefully transported to YVR, where they were loaded on to a plane, followed by two hours by car, and a trek into the marshy wetlands of Brisco, which lies along the Columbia River near the Alberta border.
Vancouver Aquarium was the first aquarium to breed the amphibians as part of an assurance population and is part of a worldwide effort, along with other zoos and aquariums, to conserve this and other amphibian species under the Amphibian Ark (AArk) project. In total, the Aquarium has reared and released almost 5,500 tadpoles since 2013.
A key component of the process involves a collaboration with Dr. Vance Trudeau at the University of Ottawa and the use of a hormone treatment he created called Amphiplex. The treatment, which is a painless injection into the frogs, has been used to help induce spawning and spur the animals into amplexus—when the male mounts and holds the female frog to induce ovulation and then fertilizes the egg masses as they are laid.
Beginning in the 1970s, populations of Northern leopard frogs across western Canada declined by the millions, making them one of the most at-risk amphibian species, especially in B.C. Research continues into the cause of these sharp declines in the Rocky Mountain population of the Northern leopard frogs. The Rocky Mountain population that occurs in B.C. is listed as Endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), and is on the provincial Red List.
Once found at many sites in the Kootenay and Okanagan regions, the Rocky Mountain population began to decrease to a point where only one wild population, in Creston Valley, existed. In 2004, a second population was reintroduced in the Upper Kootenay Floodplain, near Bummers Flats, as part of the recovery effort for this species. A third population was reintroduced in 2013 at a site in the Columbia Marshes.
There are two other populations of Northern leopard frogs in Canada; the Prairie Northern leopard frogs have reoccupied some of their former range on the Prairies, and as a result have been downlisted to be of special concern by COSEWIC. Northern leopard frogs in eastern Canada 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.