Snout to vent length 4-8 cm, females up to 10 cm. Colouration and patterning for both aquatic and terrestrial phases is extremely variable depending on time of year, age and geographic location. Dorsal colours range from tan, olive, and grey to a rich reddish-brown. The back and sides have varying levels of dark flecking, with small spots on the flanks and groin area. Hind legs have dark mottled banding (more so on the lower portion of the leg). The upper and lower lip, chin, chest and belly have various levels of mottling which becomes reduced and replaced by varying levels of red (especially on the groin and hind legs) as the frog matures. A dark eye-mask extends from the snout to around the eye and tympanum (eardrum) to the shoulder. Two light brown “dorsolateral” folds of skin run along the back from behind the eye to the groin area. Males develop a “nuptial pad” on each thumb to assist in gripping females (“amplexus”) during breeding. Tadpoles reach 2-7 cm before metamorphosing and are tan to brown with degrees of mottling and gold flecking throughout. The tail is at least as long as the body and the tailfin extends onto the back.
British Columbia’s Coast Region Species & Ecosystems of Conservation Concern SPECIES PROFILE: Northern Red-legged Frog (Rana aurora)Family Ranidae “true frogs”
BC Conservation Data Centre. 2011. [Internet] [Updated December 15 2010] BC Conservation Status Report: Rana aurora. BC MoE. -
BC Frogwatch Program. 2010. [Internet] Environmental Stewardship Division. BC Ministry of Environment. -
BC Ministry of Environment Lands and Parks. Resources Inventory Branch 1998. [Internet] Inventory Methods for Pond- breeding Amphibians and Painted Turtle (Version 2.0). Standards for Components of British Columbia's Biodiversity No. 38.
California Herps.com 2011. [Internet] Northern Red-legged Frog Rana aurora. -
COSEWIC 2004. COSEWIC assessment and update status report on the Red-legged Frog Rana aurora in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vi + 46 pp. -
Germano, J.M. and P.J. Bishop. 2008. [Internet] Suitability of Amphibians and Reptiles for Translocation. Conservation Biology 23:7-15. -
Hawkes, Virgil C. 2005. [Internet] Distribution of Red-legged Frog (Rana aurora aurora) Breeding Habitat in the Jordan River Watershed, Vancouver Island, British Columbia. BC Hydro Fish & Wildlife Bridge Coastal Restoration Program. -
Heyer, W.R., et al. 1994. Measuring and Monitoring Biological Diversity. Standard Methods for Amphibians. Smithsonian Institution Press, Washington. -
Matsuda, B.M. 2002. [Internet] The Wetlandkeepers Handbook: Section 5, Module 2.4. Conducting an Amphibian Inventory. BC Wildlife Federation, Surrey, BC. -
Maxcy, Katherine A. 2004. Accounts and Measures for Managing Identified Wildlife – Accounts V.2 Red-legged Frog Rana aurora aurora. -
Olson, D.H., Leonard, W.P., Bury, R.B. 1997. Sampling Amphibians in Lentic Habitats: Methods and Approaches for the Pacific Northwest. Northwest Fauna Number 4. Society for Northwestern Vertebrate Biology, Olympia, WA. -
Ovaska, Kristiina et al. 2004. [internet] Best Management Practices for Amphibians and Reptiles in Urban and Rural Environments in British Columbia. BC Ministry of Water, Land and Air Protection. Nanaimo. -
Sielecki, Leonard E. 2010. [Internet] Wildlife identification field guide: red and blue listed amphibians and reptiles in British Columbia. -
Proulx, Gilbert et al. 2003. A Field Guide to Species at Risk in the Coast Forest Region of British Columbia. Published by International Forest Products and BC Ministry of Environment. Victoria (BC). -
Wind E. and G. Dunsworth. 2007. [Internet] Using amphibians to monitor the effectiveness of variable retention harvesting systems on Vancouver Island.
Species Profile prepared by: Pamela Zevit, RPBio with Brent Matsuda, RPBio, and contributions from J. Malt, RPBio FLNRO for the South Coast Conservation Program (SCCP) in partnership with: International Forest Products (Interfor) and Capacity Forestry (CapFor). Original funding for this project was made possible through the Sustainable Forestry Initiative(SFI): http://www.sfiprogram.org/
Updated and revised by: Isabelle Houde, RPBio in consultation with the SCCP. Part of the National Conservation Plan, this project was undertaken with the financial support of the Government of Canada. Dans le cadre du Plan de Conservation National, ce projet a été réalisé avec l'appui financier du Gouvernement du Canada.
Every effort has been made to ensure content accuracy. Comments or corrections should be directed to the South Coast Conservation Program: firstname.lastname@example.org. Content updated March 2015. Image Credits: Northern Red-legged Frog (dorsal view): Ryan Durand, Northern Red-legged Frog (ventral view): Caroline Astley, Oregon Spotted Frog: William P. Leonard, Habitat: Pamela Zevit. Only images from “creative commons” sources (e.g. Wikipedia, Flickr, U.S. Government) can be used without permission and for non-commercial purposes only. All other images have been contributed for use by the SCCP and its partners/funders only.