SPECIES ID / Amphibians

Frogs and Toads (Anurans)

Northern Red-legged Frog


Rana aurora aurora

Identification Tips:

• Red on lower abdomen and underside of legs (may be yellow on juveniles)
• Skin folds on either side of back extend from back of eye to hip
• Skin on underside of legs is translucent
• Adults have coarse black, red and yellow mottling on hips and groin
• Adult males have enlarged thumb base
• Length 4-13 cm excluding legs

• Tail has arched crest on top that extends over rear portion of body
• Reddish and coppery flecks on underside
• To 8 cm length
• Tail 1.5 x body length or less

Egg Masses
• Large gelatinous mass (grapefruit to melon size), typically containing 500-700 eggs
• Laid underwater, but become looser, floating and frothy green with algae near hatching
• New hatchlings do not congregate in centre of egg mass, as Oregon Spotted Frog hatchlings do
• Attached to vegetation, roots or small branches in water

Conservation Status:

British ColumbiaCanadaNatureserve
COSEWICSpecies at Risk Act
Blue ListSpecial ConcernSpecial ConcernG4, S3

Life History:

• May make extensive migrations between breeding ponds, overwintering sites, and summer foraging habitats
• Sexually mature by 3rd year; may live 10 years
• Breed from late February to early April in Fraser Valley
• Males call underwater; sound similar to soft knocking on wood, may be heard from above water
• Some tadpoles may overwinter
• Adults and juveniles are carnivores; feed on a variety of invertebrates
• Tadpoles feed on algae, suspended plant material or bottom detritus
• Move mainly at night and are inactive in cold or hot, dry weather


• Breed in permanent water bodies in 50-200 cm depth, with aquatic vegetation and little or no current
• Adults use a variety forest and woodland habitats in the vicinity of water bodies.
• Sometimes found in agricultural lands, old field, or suburban areas
• May venture far from water during wet weather.
• Overwinter in small mammal burrows, or moist leaf litter


British Columbia
• Vancouver Island, Fraser Valley east to Hope
• Distribution along coast north of Fraser Valley not well known, but may exend to Kingcome Inlet
• Present on Haida Gwaii, but likely introduced

• Southwestern British Columbia to to northern California, primarily west of Cascade Mountains.

Primary Information Sources:
 Efauna BC: http://ibis.geog.ubc.ca/biodiversity/efauna/
 BC Conservation Data Centre: http://a100.gov.bc.ca/pub/eswp/