BC List Status:
Red (Candidates for- Extirpated, Endangered, or Threatened status)
Oregon Spotted Frog shares distribution with other “Ranid” frogs including Northern Red-legged Frog, Green Frog and Bullfrog. Coloured ventral area on Northern Red-legged Frog tends to be a distinct bright red while Oregon Spotted Frog is more of a dark, rust-orange colour. Northern Red-legged Frog tadpoles have yellow to washed out red bellies with gold flecks while Oregon Spotted Frog tadpoles have white or slate coloured bellies. Oregon Spotted Frog tends to sit with its belly low to the ground while most other Ranid species sit upright. The upturned eyes and extensive webbing on the hind feet are key diagnostics for Oregon Spotted Frog. Skin on legs is opaque, as opposed to Northern Red-legged Frog where skin is transparent with muscles / bones visible through skin
Habitat loss from draining and infilling of wetlands, and hydrological disruption of surface and groundwater due to urbanisation.
Egg mortality from vulnerability of breeding sites (large shallow wetlands) to fluctuating water levels causing stranding and washing away of egg masses. May become an increasing issue with climate change.
Population isolation and reduced dispersal of remaining populations.
Disturbance of hydrological processes and isolation of populations due to roadways.
Predation by introduced Bullfrog and potential competition impacts from Green Frog
Habitat alteration from invasion of non-native plant species (e.g. species of reed canary grass).
Cumulative impacts from disease. Chytridiomycosis, caused by the chytrid fungus Batrachochytrium dendrobatidis, has been linked to dramatic population declines or even extinctions of amphibian species in western North America and has been found to occur w
Sensitivity to water chemistry (i.e. conductivity), especially during embryonic development. This species may require specific conditions for optimal reproductive success.
Sensitivity to water chemistry (i.e. conductivity), especially during embryonic development. This species may require specific conditions for optimal reproductive success.
Direct mortality or sub-lethal impacts throughout all life history phases from fertilizer and pesticide applications in urban and agricultural areas as well as for silviculture management.
Please consult the Recovery Strategy for the Oregon Spotted Frog (Rana pretiosa) in Canada (2015), and “Develop with Care’s BMP’s for Amphibians and Reptiles in Urban and Rural Environments in British Columbia”. Complementary objectives can be found in “A Conservation Assessment for the Oregon Spotted Fropg Rana pretiosa” through the USDA Forest Service Region 6 and USDI Bureau of Land Management, Oregon and Washington. Inventory and monitoring resources include standardized methods (Resource Information Standards Committee) # 37 Inventory Methods for Pond-breeding Amphibians and Painted Turtle (Version 2.0)”, “Measuring and Monitoring Biological Diversity - Standard Methods for Amphibians”, “Suitability of Amphibians and Reptiles for Translocation” and amphibian survey methodologies developed for the “Wetlandkeepers Handbook”.