Checklist of Amphibian Species and Identification Guide
Columbia Spotted Frog, Rana luteiventris
Oregon Spotted Frog, Rana pretiosa
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| The Columbia Spotted Frog and the Oregon Spotted Frog were long regarded as the same species (the Spotted Frog, Rana pretiosa). Earlier studies suggested that there was sufficient regional variation to warrant divided populations among two subspecies. More extensive data has shown , however, that these morphological differences were not consistent and the subspecies designations were abandoned. Since then, however, studies looking at genetic differences between populations found sufficiently large differences to conclude that Rana pretiosa consisted of at least two cryptic species, now called R. luteiventris and R. pretiosa, with distributions as shown in the range map (see Green et al. 1997 for more details). Although the two species can not be reliably distinguished by morpholology, the two species have allopatric (non-overlapping) ranges, so they may be reliably identified based upon the location where a frog is found. |
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| The range map also shows the historical ranges where the Oregon Spotted Frog has not been found for quite some time and is thought to have been extirpated. If you do find an Oregon Spotted Frog in these areas report it a state herpetologist. Possible reasons for this decline are the introduction of the American Bullfrog, which preys on smaller frogs, and general habitat alteration and loss through intensified agriculture, grazing and urbanization. The range shown in the map follows Green et al. (1997). |
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| The two species may be tan, gray, brown, reddish-brown or red above with irregular-shaped black spots with indistinct edges and light centers. They have upturned eyes, relatively short hind legs and extensive webbing between the toes of the hind feet. Females reach sizes of up to 4 inches in snout-ventor length and become larger than males which reach up to 3 inches in length. They have a light stripe on the lower jaw and dorsolateral folds or ridges are usually present. |
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| The undersides are usually cream colored, but the lower abdomen and the undersides of the hind legs are usually colored by a reddish-orange or salmon-colored pigment, as in the photo to the lower left. However, in some populations of the Columbia Spotted Frog in Nevada, Utah, Idaho south of the Salmon River and southeast Oregon (but not in the Blitzen River or its tributaries) the underside tends to be yellow as in the photo to the lower right. |
Additional photos of the Columbia Spotted Frog from Wyoming.   |
Photos of the Columbia Spotted Frog from Utah.   |
Reference:Green, D. M., H. Kaiser, T. F. Sharbel, J. Kearsley, and K. R. McAllister. 1997.
Cryptic species of Spotted Frogs, Rana pretiosa complex, in western North
America. Copeia 1997(1): 1-8. |
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