Over the past few monthsA team of amphibian heroes is helping the endangered northern leopard frog rediscover its home in Western Canada by releasing a total of 1,929 tadpoles into British Columbia wetlands, including Creston and Kimberley.
The Wilder Institute/Calgary Zoo (WICZ) works with other conservation organizations, governments, zoos and aquariums to breed, relocate and release frogs in BC, where only one wild population of northern leopard frogs exists.
The northern leopard frog occurs in three populations in Canada – the eastern population, the western boreal/steppe population, and the Rocky Mountain population. The Rocky Mountain population found in BC is endangered. This frog plays an important role in its ecosystem in transferring nutrients between terrestrial and aquatic environments. WICZ is part of the British Columbia Northern Leopard Frog Recovery Team and is working with 13+ collaborators to save this frog.
Relocating thousands of tiny leaf litter is no easy task. Therefore, this recovery program uses multiple conservation translocation methods to allow the greatest number of tadpoles to be released into the wild. From egg to frog, this species has expert support at every step of its life cycle.
Starting in early spring, biologists listen for male frogs at the Creston Valley Wildlife Management Area, where the last remaining population of northern leopard frogs exist in B.C. lays eggs soon.
For several weeks, biologists conducted surveys to find the large egg masses produced by northern leopard frogs. Once settled, they kept the egg masses safe using a fine mesh enclosure where they could protect the newly hatched tadpoles from predators.
Those tadpoles were either released at Creston, transferred to the reintroduction site, brought to conservation hatcheries to produce future eggs for reintroduction, or hatched and released to the reintroduction site at the end of the season.
This year, some tadpoles from Creston were immediately relocated to a release site near the Kimberley on property managed and managed by the Nature Conservancy of Canada (NCC) and private landowners.
This is the first time we have moved northern leopard frogs to this area. Four separate wetlands here were selected as release sites based on habitat suitability criteria such as water depth, vegetation and dissolved oxygen levels.
Before being released into these wetlands, the sticklebacks acclimate to their new home by doing a series of water changes in their holding tanks. This ensures that differences in water from site to site are not shocking to the little tadpoles.
This year, 1,602 tadpoles were transplanted using this method.
Other tadpoles were also taken into care for the Edmonton Valley Zoo’s head start program. The 327 tadpoles were cared for in a controlled environment for about three weeks, where they were protected from predators and received the nutrients they needed to develop a healthy body condition. This allowed the tadpoles to grow and be released with a better chance of survival. Some individuals also retreated to help produce pups for release in future years.
Conservation breeding involves carefully managed conservation breeding populations under the supervision of animal care professionals. Once established, conservation breeding programs can contribute genetically diverse individuals to the wild. Through this program, male and female frogs are encouraged to reproduce safely.
WICZ, the Vancouver Aquarium, and the Edmonton Valley Zoo have hosted conservation breeding programs for the northern leopard frog since 2017, 2009, and 2020, respectively.
WICZ’s breeding program is designed to closely replicate wild conditions while encouraging natural behaviors such as husbandry. As well as encouraging natural reproduction, the team will offer hormone support, and have seen frogs respond to this method with eggs produced in the past.
WICZ’s new state-of-the-art conservation facility, the Archibald Biodiversity Center, which recently opened this summer, will allow more space for the team to continue their breeding efforts.
What comes next?
From July to September, WICZ researchers will monitor the released frogs each week to see how they adapt to their new home near the Kimberley.
During this time, the frogs will metamorphose into frogs and eventually become adults. In the spring, the researchers will return to check whether the frogs have successfully overwintered and reproduced.
Each frog has a unique spotting pattern that will help researchers identify them and better understand how many of the released tadpoles successfully make it to the next stage of their life cycle, which they hope will eventually give the population new sharks. In a recent weekly monitoring survey, researchers observed the little northern leopard frog for 109 years.
This is three times more than what we found during our weekly surveys at the same time of year at the previous reintroduction site. The team is excited about these promising numbers found at the Kimberly reintroduction site.
Learn more about our Northern Leopard Frog Conservation Program.
The Wilder Institute/Calgary Zoo is proud to partner with the British Columbia Northern Leopard Frog Recovery Team, BC Ministry of Land, Water and Resource Management and Ministry of Forests, Creston Valley Wildlife Management Area, Edmonton Valley Zoo, Fish and Wildlife Compensation Program. The Nature Conservancy of Canada and the Vancouver Aquarium. The success of this important program would not be possible without their continued support.
Lead image: Northern leopard frogs. Photos are provided
Presented by The Wilder Institute/Calgary Zoo