Rana pretiosa


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Rana pretiosa
Species Authority: Baird and Girard, 1853
Common Name(s):
English Oregon Spotted Frog
Taxonomic Notes: Rana luteiventris was included in this species before it was elevated to species status by Green et al. (1996, 1997).

Assessment Information [top]

Red List Category & Criteria: Vulnerable A2ace ver 3.1
Year Published: 2004
Date Assessed: 2004-04-30
Needs updating
Assessor(s): Geoffrey Hammerson, Christopher Pearl
Reviewer(s): Global Amphibian Assessment Coordinating Team (Simon Stuart, Janice Chanson, Neil Cox and Bruce Young)
Listed as Vulnerable because of an observed population decline, estimated to be more than 30% over the last three generations, inferred from a decline in its area of occupancy, and from the effects of introduced predators and habitat degradation. The generation length is assumed to be five years.
1996 Not Evaluated

Geographic Range [top]

Range Description: This species can be found in south-western British Columbia, Canada, south through the Puget/Willamette Valley trough and the Columbia River gorge in south-central Washington to the Cascades range at least to the Klamath Valley in Oregon, USA. It has been extirpated from much of western Oregon and Washington. Some records are based on misidentified Rana aurora (Green et al. 1997). Historically, it has occurred in north-eastern California (Jennings and Hayes 1994, Hayes 1994). It occurs at an elevation of 20-1,570m asl.
Canada; United States
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: It is now known from ca. 33 sites in the north-western United States and south-western British Columbia, Canada (Pearl and Hayes 2005). Most extant populations are small. The Conboy Lake NWR population produced a five-year maximum-estimated at 8,300 egg masses in one year in the late 1990s, but then plummeted to about 1,500 egg masses in 2003 (M. Hayes, unpubl.). Historically, it is recorded from eight localities in western Washington, 44 in Oregon, three in California, and one in British Columbia. A nearly complete survey of the range in the mid-1990s revealed extant populations only in three sites in Washington and 19 in Oregon. It is apparently extirpated in California (M. Hayes), but recently confirmed as extant in the Fraser Valley, British Columbia (D. Green pers. comm.).The species has probably vanished from about 70-90% of its former range.
Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: It is highly aquatic, and rarely found far from permanent quiet water; usually occurs at the grassy margins of streams, lakes, ponds, springs, and marshes (Licht 1971, 1986, Watson, McAllister and Pierce 2003). Animals may disperse into forest, grassland, and brush land during wet weather. It breeds usually in shallow water in ponds or other quiet waters. It does not appear to adapt well to habitat disturbance or alteration, although it does occur in some anthropogenic ponds in central Oregon (C. Pearl, unpubl.).
Systems: Terrestrial; Freshwater

Threats [top]

Major Threat(s): It has declined in areas inhabited by the introduced bullfrog (Pearl et al. 2004). Introduced predatory fishes probably also are having a detrimental impact. The decline of this species is also probably related to loss and degradation of breeding habitat such as may result from dam construction, alteration of drainage patterns, dewatering due to urban and agricultural use of water, excessive livestock grazing, and other human activities that reduce or eliminate lentic shallow water. At the embryonic stage, UV-B radiation currently does not seem to be contributing to population declines (Blaustein et al. 1999).

Conservation Actions [top]

Conservation Actions: It is somewhat protected in several federal and state parks and refuges, though management usually ignores this species. Some zoos in North America have raised wild-caught larvae and then reintroduced them to the wild, although captive breeding of this species has not yet been successful.

Bibliography [top]

Behler, J.L. and King, F.W. 1979. The Audubon Society Field Guide to North American Reptiles and Amphibians. New York.

Blackburn, L., Nanjappa, P. and Lannoo, M.J. 2001. An Atlas of the Distribution of U.S. Amphibians. Ball State University, Muncie, IN, USA.

Blaustein, A.R., Hays, J.B, Hoffman, P.D., Chivers, D.P., Kiesecker, J.M., Leonard, W.P., Marco, A., Olson, D.H., Reaser, J.K. and Anthony, R.G. 1999. DNA repair and resistance to UV-B radiation in western spotted frogs. Ecological Applications: 1100-1105.

Briggs Sr, J.L. 1987. Breeding biology of the Cascade frog, Rana cascadae, with comparisons to R. aurora and R. pretiosa. Copeia: 241-245.

Corn, P.S. and Vertucci, F.A. 1992. Descriptive risk assessment of the effects of acidic deposition on Rocky Mountain amphibians. Journal of Herpetology: 361-369.

Frost, D.R. 1985. Amphibian Species of the World: A Taxonomic and Geographic Reference. Allen Press and the Association of Systematic Collections, Lawrence, Kansas.

Green, D.M. 1986. Systematics and evolution of western North American frogs allied to Rana aurora and Rana boylii: electrophoretic evidence. Systematic Zoology: 283-296.

Green, D.M. 1986. Systematics and evolution of western North American frogs allied to Rana aurora and Rana boylii: karyological evidence. Systematic Zoology: 273-282.

Green, D.M., H. Kaiser, Sharbel, T.F., Kearsley, J. and McAllister, K.R. 1997. Cryptic species of spotted frogs, Rana pretiosa complex, in western North America. Copeia: 1-8.

Green, D.M., Sharbel, T.F., Kearsley, J. and Kaiser, H. 1996. Postglacial range fluctuation, genetic subdivision and speciation in the western North American spotted frog complex, Rana pretiosa. Evolution: 374-390.

Hayes, M.P. 1994. Current status of the spotted frog (Rana pretiosa) in Western Oregon. Final report to ODFW, pp. 13 pp.

IUCN. 2004. 2004 IUCN Red List of Threatened Species. Downloaded on 23 November 2004.

Jennings, M.R. and Hayes, M.P. 1994. Amphibian and reptile species of special concern in California. Final Report submitted to the California Department of Fish and Game, Inland Fisheries Division. Contract No. 8023.

Licht, L.E. 1971. Breeding habits and embryonic thermal requirements of the frogs, Rana aurora aurora and Rana pretiosa pretiosa, in the Pacific Northwest. Ecology: 116-124.

Licht, L.E. 1986. Food and feeding behavior of sympatric red-legged frogs, Rana aurora, and spotted frogs, Rana pretiosa, in southwestern British Columbia. Canadian Field-Naturalist: 22-31.

Nussbaum, R.A., Brodie, Jr., E.D. and Storm, R.M. 1983. Amphibians and Reptiles of the Pacific Northwest. University Press of Idaho, Moscow, ID, USA.

Pearl, C.A., Adams, M.J., Bury, R.B. and McCreary, B. 2004. Asymmetrical effects of introduced bullfrogs (Rana catesbeiana) on native ranid frogs in Oregon, USA. Copeia: 11-20.

Pearl, C.A. and Hayes, M.P. 2005. Rana pretiosa, Oregon spotted frog. In: Lannoo, M.J. (ed.), Status and Conservation of U.S. Amphibians. Volume 2: Species Accounts, University of California Press, Berkeley, California.

Spahr, R., Armstrong, L., Atwood, D. and Rath, M. 1991. Threatened, endangered, and sensitive species of the Intermountain Region. U.S. Forest Service, Ogden, Utah.

Species at Risk Branch. 2002. Species at Risk Range Maps. Canadian Wildlife Service, Environment Canada. (, Ottawa.

Turner, F.B. and Dumas, P.C. 1972. Rana pretiosa. Catalogue of American Amphibians and Reptiles: 1-4.

Washington Department of Wildlife. 1991. Spotted Frog Rana pretiosa. Unpublished report from Washington Department of Wildlife, Olympia.

Watson, J.W., McAllister, K.R. and Pierce, D.J. 2003. Home ranges, movements, and habitat selection of Oregon spotted frogs (Rana pretiosa). Journal of Herpetology.

Citation: Geoffrey Hammerson, Christopher Pearl 2004. Rana pretiosa. The IUCN Red List of Threatened Species. Version 2015.2. <>. Downloaded on 02 September 2015.
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