What is the Precious Frog Program?

The Precious Frog program works to recover the endangered Oregon Spotted Frog and the wetland ecosystems that sustain it. This program works closely with the Provincial Oregon Spotted Frog Recovery Team to enhance habitats, identify and control threats, and implement recovery actions.


Did you know? The scientific name for Oregon Spotted Frog, Rana pretiosa, literally means “precious frog”.

Oregon Spotted Frogs Are At Risk

The Oregon Spotted Frog is one of Canada’s most endangered amphibians. In Canada, it is only found in the Fraser Valley.




Estimated total number of adults remaining



In the Fraser Valley




10-year extinction probability for 5 populations

Across the globe, amphibians are in crisis. Over 30 percent of known amphibian species are considered globally endangered, and many more are “threatened.” British Columbia is no different. Of our twenty native amphibian species, five are red-listed (endangered or threatened), and five are blue-listed (special concern) in the province.


Learn more about why native amphibians are at risk in the Fraser Valley.


Loss of Wetland Habitat

Land use changes since European settlers arrived in the Fraser Valley have resulted in the elimination of seasonal marshes and shallow wetlands in the Fraser Valley, with remnant populations of frogs squeezed into agricultural ditches or deeper pools and channels.


The Oregon Spotted Frog is associated with medium to large wetlands, which are shallow, slow moving, and warm. These wetlands also typically have a portion that is permanently wetted and have an abundance of native grasses, sedges, or rushes.


Within these wetlands, a diversity of microhabitats is required depending on life stage, season, and weather conditions. For example, breeding sites tend to be seasonally flooded areas along sun‐exposed sloping benches. Stable water levels are critical for survival of eggs and tadpoles. Fluctuations in water levels can result in leaving the young dry and exposed. Adults are known to take refuge in deep pools during dry periods and burrow into soil or mud along wetland edges, and hide in beaver dams and lodges during cold periods.


Efforts to enhance and restore wetlands occupied by the Oregon Spotted Frog have a positive impact on aquatic plant, invertebrate, and vertebrate populations that live in or visit the wetlands, and benefit other species at risk such as Red-legged Frog, American Bittern, Great Blue Heron, Green Heron, the Salish Sucker, and the Pacific Water Shrew.

Isolated Populations

As wetlands and floodplains were eliminated, connections between watersheds and waterways were lost, trapping the aquatic Oregon Spotted Frogs into linear stream systems that may not be able to sustain a population due to lack of permanent water, unsuitable habitat features, or too few frogs to maintain genetic integrity and survive environmental pressures. Some, however, have survived in these modified ecosystems, and it seems that with some careful planning, and a better understanding of the frogs’ needs and sensitivities, these frogs can survive (and maybe even thrive) in a shared-use agricultural landscape.


We believe that more populations may be out there – but they are hard to find! The most likely people to find new populations are environmental technicians and monitors working with farmers, municipalities and developers in stream channels. Two of the six known populations were found as recently as 2014, both by technicians who were working on fish research and ecological monitoring. By educating field technicians and frog-catching kids, we hope to identify more populations in the Fraser Valley, and improve our understanding of how people and frogs can coexist on the same landscape.

Invasive Species

OSF must also compete with invasive species such as Bullfrogs and Green Frogs, and face the loss of their specialized breeding habitat due to invasive plant species like Reed Canarygrass.


Bullfrogs, native to Eastern Canada, were accidentally introduced to B.C. fifty years ago. These large frogs can eat Oregon Spotted Frogs and other smaller frogs, and wetlands where Bullfrogs are found have much smaller populations of native amphibians Oregon Spotted Frog and other amphibians are also highly sensitive to pollutants because of their permeable skin. They are exposed to agricultural chemicals and pesticides used within the channel banks or unsafely stored adjacent to the watercourses.

Learn more about Bullfrogs in our Bullfrogs and Biodiversity program.


Disease and Environmental Pressures

The Oregon Spotted Frog is also susceptible to fungal diseases like Chytridiomycosis, which affects around 30 percent of the planet’s amphibian species. This disease is responsible for dramatic amphibian declines, and there is no known cure.


Amphibians are particularly sensitive to changes in the environment, particularly those that affect water and temperature conditions. They rely on environmental conditions to regulate their body temperature, and physical changes in habitat, like draining wetlands or removing vegetative cover, can dramatically alter thermal conditions. Climate disruption is a serious threat to amphibians, and most are not equipped to move ahead of climactic changes.


They are exposed to a wide range of aquatic pollutants during their sensitive egg and tadpole development phases. This can result in slow or abnormal development that affects their survival and their own ability to reproduce.

What Does the Precious Frog Program Do?

We have worked to protect these Precious Frogs and their habitats since 2010.

Habitat enhancement

We work to restore shallow wetland habitats across the Fraser Valley with a "frog friendly" focus.

Collaborative research

Alongside the Oregon Spotted Frog Recovery Team, we work to learn more about this elusive species to aid recovery actions.

Community education

We raise awareness of amphibians at risk and the importance of wetland habitats to people across the Fraser Valley.

Stewardship advice

We support landowners with stewardship of frog habitat on their properties through our Nature Stewards program.
Nature Stewards Program

Professional training

We train environmental professionals in frog and egg mass identification techniques, and habitat recognition.
Request Training

Searching for frogs

We search for new populations of amphibians at risk across the Fraser Valley. Have you seen this frog? Let us know!
Submit an Observation