Canada's Most Endangered Amphibian

Background

The Oregon Spotted Frog (Rana pretiosa) is Canada’s most endangered amphibian, only existing in the lower Fraser Valley in British Columbia this side of the border. “Rana pretiosa” translates directly to “precious frog”. Aptly named as roughly only 300 Canadian individuals remain in the wild, these frogs are indeed rare and precious. The frogs were once spread all the way west through the lower mainland, and south down through Washington, Oregon, and Northern California. The frog’s historical range has dwindled by 90%, almost exclusively thanks to human impact. In Canada (and only in the Fraser valley exclusively), the frogs have been reduced to just 3 populations. Worse still, these populations are highly fragmented and are no longer connected. Their isolation is detrimental to the genetic diversity of the species.

Why do amphibians such as the Oregon Spotted Frog matter?

In addition to having an intrinsic right to exist, amphibians such as the Oregon Spotted Frog serve a direct purpose in the food chain, eating a multitude of insects. They are also excellent bioindicators. Frogs are sensitive to even the most minute environmental changes, and it has been proven that Oregon Spotted Frogs are even more sensitive than many amphibians. These changes can include differences in temperature, humidity, and water purity. With only a thin layer of mucousy membrane to protect its body, they are particularly susceptible to toxins, bacteria, and disease. Amphibians serve as reliable indicators of their surroundings because of how these factors can impact them. For example, a marsh or wetland that is inhabited by fragile spotted frogs is a good sign that the ecosystem is healthy. Surrounding marshes that no longer feature the amphibian may have undergone serious ecological stress, such as with the various anthropogenic factors highlighted below.

Plight of the Oregon Spotted Frog

Specific reasons for their decline include habitat degradation (agricultural and development), invasive species, resource extraction, and alterations to the water bodies they inhabit. The draining of Sumas Lake to make way for farmland took place just over 100 years ago in one of its prime territories, which was particularly devastating to the fragile amphibian. In addition, Oregon Spotted frogs have been a deadly target for the chytrid

Fungi, causing chytridiomycosis in amphibians. Invasive species such as the American Bullfrog and Reed Canarygrass have also been highly destructive to the frogs. Highly resilient bullfrogs will eat anything and everything that fits into their mouths, and canarygrass has proven to be quite negatively impactful to the frog’s breeding habitats.

What is being done to help the frogs

The Oregon Spotted Frog is protected by the Wildlife Act in British Columbia, unfortunately rather flimsily. Despite being on the precipice of extinction, the dwindling territory of Oregon Spotted Frog is not protected by law. Historically, the frogs have been aided by scientists, conservationists, first nations, students, and emboldened citizens. A recovery team was put together in 1999, which resulted in the first case of emergency federal protection under COSEWIC. The newly declared endangered frog was given priority so conservation work such as surveys and environmental monitoring could take place immediately. Modern recovery efforts involving the Greater Vancouver Zoo, Vancouver Aquarium, Fraser Valley Conservancy, Seabird Island and Sts’ailes First Nations, and the BC government work in conjunction with each other in an effort to boost the remaining populations of the frogs. The aquarium and zoo head captive breeding programs that produce a large amount of tadpoles that are released into existing Oregon Spotted Frog habitat. Additionally, surveys and monitoring are consistent during the breeding season. Finding new and existing egg clusters are important, but so too would be the discovery of a new breeding territory which may prove the existing conservation work to be succeeding.

How you can help

Though ideally the largest scale protections would be tackled by the provincial government (Fact: British Columbia STILL does not have  endangered species or species at risk legislation), there are other ways the every day conservationist can make a difference. Wildlife Preservation Canada encourages the public to collect waste along shorelines, never take native wildlife from its habitat, watch for reptiles and amphibians on the road, reduce daily water use, eliminate the use of pesticides, never purchase captive wildlife taken from the wild, plant native species, and put pressure on elected officials to enact permanent protections (such as the formation of endangered species legislation, or permanent habitat protection of the Oregon Spotted Frog).

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About the Author

Ray Maichin is a wildlife, nature, and conservation photographer based out of Delta, BC! Growing up in British Columbia, Ray took an early interest in our local wildlife, particularly reptiles and amphibians. Eventually, he was inspired to go to school to get his BSc and take the next steps towards a career in conservation. He is currently working on the beginning stages of that career, working with some wonderful people on a Western Painted Turtle recovery project! His future goal is to intertwine his passion for conservation photography and his growing interest in underwater shooting and videography. His short term goal is to put a spotlight on wildlife such as turtles, frogs, snakes, fish. When not working or shooting, Ray enjoys camping, concerts, and attempting new vegetarian recipes!