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Electronic Field Guide to the
Reptiles and Amphibians of
Southern California
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Adult, green phase, Grant County, Washington |
Adult, brown phase, Grant County, Washington |
Adult, green phase, Grant County, Washington |
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Adult, Grant Co., Washington |
Adult, green phase, Grant County, Washington |
Adult, brown phase, Grant County, Washington |
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Underside |
Adult, Grant County, Washington |
Groin of adult |
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| Adult, Washington County, Utah |
Adult, Washington County, Utah |
Adult, Washington County, Utah |
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| Adult, Washington County, Utah |
Adult, Washington County, Utah |
Adult, Grant County, Washington |
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| Eggs, Washington County, Utah |
Eggs, Washington County, Utah |
Eggs, Washington County, Utah |
Habitat |
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Introduced habitat - agricultural canal, Merced County
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Habitat, Tule Lake, 4,100 ft., Siskiyou county |
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Possible former Habitat, Owens River,
Inyo County
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Possible former Habitat, Owens Valley,
Inyo County |
Close-up of breeding pond during the spring breeding season, Grant County, Washington |
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Short Videos |
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Two videos of a Northern Leopard Frog calling on a sunny April afternoon in Grant County, Washington. Red-winged blackbirds and yellow-headed blackbirds and other birds are heard in the background. Calling was sporadic over a long period of time, so these calls have been edited together from longer videos.
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A pond with a few of the last remaining Northern Leopard Frogs in Grant County, Washington. |
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A Northern Leopard Frog on the rocky shore of a river in Washington County, Utah. |
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Description |
Size |
| A medium-sized slender frog. Adults are 2 - 4 3/8 in. long from snout to vent (5.1 - 11.1 cm). Females are larger - males grow up to 3 1/8 in. (8 cm). |
| Appearance |
Green, tan, or brown above, with dark brown oval spots with well-defined edges and pale borders. Creamy white below,
without any dark pigmentation. Cream-colored well-defined dorsolateral folds extend from the shoulders to the rump.
The upper jaw has a whitish stripe. Young have few or no spots. Tadpoles are brown or grey with small gold spots, creamy
below with a bronzy sheen and visible guts, and grow up to 3.5 in. in length (8.9 cm.) |
| Voice |
| A low gutteral snore-like rattle, which has been compared to a small motor boat engine. Calls at night and occasionally during the day. Often screams when captured or when startled and jumping into water. |
| Behavior |
Diurnal and nocturnal. Very well-adapted to cold conditions. Often strays far from water in summer into a variety of habitats including hay fields and grassy woodlands, as long as there is sufficient vegetative cover for concealment. Adults and juveniles may wander around in wet weather.
Hibernates in winter, typically under large deep bodies of water that do not freeze to the bottom, positioned under rocks or logs or in pits, or buried under mud. Frogs will die if the water does not contain enough oxygen or if they freeze more than aproximately 8 hours.
Frogs avoid predators by sitting still or by jumping in to water and hiding in vegetation, and tadpoles reduce their activity.
Longevity has been recorded as long as 9 years in captivity.
Typically, a frog sits and waits until prey comes close. When the frog sees the prey moving, it moves and lunges after it, using its large sticky tongue to catch the prey and bring it into the mouth to eat. Eating takes place out of the water. Watch a slow-motion feeding video here.
Tadpoles feed by grazing on plant tissue and bacteria by scraping plant surfaces with their mouth parts. Algae and detritus and possibly carrion are also consumed. |
| Diet |
| Eats invertebrates, leeches, fish, amphibians, snakes, and small birds. |
| Reproduction and Young |
Reproduction is aquatic. Fertilization is external. After emerging from hibernation, frogs move to breeding waters from winter hibernacula, unless they hibernate and breed in the same pond. Calling, mating and egg-laying occurs for a short period anytime from March to July after the snow melts. (Breeding has also been recorded in September and October in New Mexico.) Breeding habitat is varied, and includes quiet waters along streams and rivers, permanent ponds and lakes, cattle ponds, agricultural ditches, flooded fields, and beaver ponds. Temporary ponds and pools are also used. Bodies of water with or without vegetation are both used. Males gather at breeding sites and make a breeding call at night, and occasionally during the day. Females become reproductively mature at 2 - 3 years, males at 1 - 2 years. Females lay eggs once per year.
Eggs are laid in densely-packed, flat, rounded clusters the size of a grapefruit - around 4.5 in. (11.5 cm) in diameter, and are attached to vegetation under water, or rarely, left to lie on the bottom of still water. Several egg masses may be attached together communally. Egg masses of between 645 and 7,648 eggs have been reported. Eggs hatch into tadpoles in 2 - 17 days, depending on temperature.
Tadpoles transform into frogs 3 - 6 months after eggs are laid. At one location, tadpoles metamorphosed 50 days after hatching. Tadpoles have also been observed overwintering. Tadpoles are diurnal and do not form schools. Newly-metamorphosed juveniles are about 1 inch. long. (2.5 cm.) Juveniles disperse from breeding waters. |
| Range |
Native to northern California, but also introduced in California (and throughout the west) in the past 100 years, possibly partly due to escapees from widespread use of the species for study and dissection in biology classes. Introduced at Lake Tahoe, and in the Central Valley.
The overall range of this species is from most of southern Canada, across most of the northern United States, with scattered locations in the northwest, south in the west through Arizona and almost to the Mexican border in New Mexico.
Historical populations in California existed in scattered locations below 6,500 ft. (1981 m.) in the far Northeast
part of the state, in Siskiyou and Modoc counties, in the northern Owens Valley, and possibly near Lake Tahoe. The origin of the lake Tahoe population is questionable, because leopard frogs were transplanted from a reservoir in Nevada to the southwest shore of Lake Tahoe in the early 20th century, in order to provide a source of fresh frog legs for a local restaurant. (Jennings 2004)
Jennings and Fuller determined in their 2004 report on the distribution of leopard frogs in California that Northern leopard frogs are "...native to the region east of the Sierra nevada-Cascade crest.... Early in the 20th century (Northern leopard frogs) expanded their ranges into favorable habitats created by water diversions and large-scale irrigation projects. Since the 1970s, northern leopard frogs seem to have disappeared from most of their historic range.... Northern leopard frogs of unknown origin were introduced into El Dorado, Kern, Los Angeles, Merced, San Francisco, Sierra, Tehama, and Tulare counties between 1905 and 1970. Several of these introduced populations experienced rapid growth and range expansions before completely disappearing. Except for a small population of northern leopard frogs present in Merced County, all of these introduced populations have apparently perished after persisting for varying periods of 5 -25 years."
According to Storer (1925) "An attempted introduction of pipiens in the northern Sacramento Valley was made in 1918 when stocks (source unknown) were planted on ranches east of Red Bluff (Elliot and Hickman ranches) and at Battle Creek Meadows [=Mineral Postoffice], altitude 4500 ft. Mr. D. G. Maclise, who was instrumental in placing these frogs, reported that in 1920 the frogs near Red Bluff were "thriving"; but efforts to obtain specimens in 1924 were unavailing. Pipiens is the species of frog used most commonly in physiological laboratories, and is also sought commercially for 'frogs-legs'; other attempts of planting may therefore have been made within California." |
| Habitat |
Inhabits grassland, wet meadows, potholes, forests, woodland, brushlands, springs, canals, bogs, marshes, reservoirs.
Generally prefers permanent water with abundant aquatic vegetation.
From sea level to 11,000 ft. (3,350 m.) |
| Taxonomic Notes |
In 2006, Frost et al divided North American frogs of the family Ranidae into two genera, Lithobates and Rana. Rana is still used in most existing references.
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| Conservation Issues (Conservation Status) |
This species has experienced severe declines in the west, including most historical localities in California, Washington, Oregon, Arizona, New Mexico, and Western Montana. Declines have also occurred in Nevada, Wyoming, and Idaho. In other areas across the country, some populations are doing well, while others have also shown declines.
Northern Leopard Frogs are absent and possibly extirpated from about 95 percent of their historical range in California. Recent records are from one national wildlife refuge near the Oregon border and in the Owens Valley, northwest of Bishop. Most of the habitat previously inhabited in the Modoc and Owens Valley regions have been severely altered by agriculture and grazing, and introduced predators such as bullfrogs, crayfish, and exotic fishes may have negatively affected populations of R. pipiens. Disease, parasites, agricultural chemical pollution, and UV-B radiation have all been reported to cause declines and malformations of adult frogs and tadpoles. |
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Taxonomy |
| Family |
Ranidae |
True Frogs |
| Genus |
Lithobates |
American Water Frogs |
| Species |
pipiens |
Northern Leopard Frog
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Original Description |
Schreber, 1782 - Naturforscher, Vol. 18, p. 185, pl. 4
from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz
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Meaning of the Scientific Name |
Lithobates - Greek
- Litho = a stone, bates = one that walks or haunts
pipiens - Latin - peeping - the collector heard Spring Peepers, collected this species thinking that the loud whistle came from the larger frog.
from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz
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Alternate Names |
Rana pipiens
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Related or Similar California Frogs |
Lithobates berlandieri
Lithobates catesbeianus
Lithobates yavapaiensis
Rana draytonii
Rana aurora
Rana boylii
Rana cascadae
Rana pretiosa
Rana muscosa
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More Information and References |
Natureserve Explorer
California Dept. of Fish and Game
AmphibiaWeb
Jennings, Mark R., and Michael M. Fuller. 2004. Origin and distribution of leopard frogs, Rana pipiens complex, in California. California Fish and Game 90(3):119-139.
Stebbins, Robert C., and McGinnis, Samuel M. Field Guide to Amphibians and Reptiles of California: Revised Edition (California Natural History Guides) University of California Press, 2012.
Stebbins, Robert C. California Amphibians and Reptiles. The University of California Press, 1972.
Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians. 3rd Edition. Houghton Mifflin Company, 2003.
Behler, John L., and F. Wayne King. The Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, 1992.
Powell, Robert., Joseph T. Collins, and Errol D. Hooper Jr. A Key to Amphibians and Reptiles of the Continental United States and Canada. The University Press of Kansas, 1998.
Macey, J. Robert and Theodore Papenfuss."Herpetology." The Natural History of the White-Inyo Range Eastern California.
Ed. Clarence Hall. University of California Press, 1991.
Corkran, Charlotte & Chris Thoms. Amphibians of Oregon, Washington, and British Columbia. Lone Pine Publishing, 1996.
Jones, Lawrence L. C. , William P. Leonard, Deanna H. Olson, editors. Amphibians of the Pacific Northwest. Seattle Audubon Society, 2005.
Leonard et. al. Amphibians of Washington and Oregon. Seattle Audubon Society, 1993.
Nussbaum, R. A., E. D. Brodie Jr., and R. M. Storm. Amphibians and Reptiles of the Pacific Northwest. Moscow, Idaho: University Press of Idaho, 1983.
Conant, Roger, & Joseph T. Collins. A Field Guide to Reptiles and Amphibians Eastern and Central North America.
Third Edition, Houghton Mifflin Company, 1998.
Bartlett, R. D. & Patricia P. Bartlett. Guide and Reference to the Amphibians of Western North America (North of Mexico) and Hawaii. University Press of Florida, 2009.
Elliott, Lang, Carl Gerhardt, and Carlos Davidson. Frogs and Toads of North America, a Comprehensive Guide to their Identification, Behavior, and Calls. Houghton Mifflin Harcourt, 2009.
Lannoo, Michael (Editor). Amphibian Declines: The Conservation Status of United States Species. University of California Press, June 2005.
Wright, Anna. Handbook of Frogs and Toads of the United States and Canada. Cornell University Press, 1949.
Storer, Tracy I. A Synopsis of the Amphibia of California. University of Califonia Publications in Zoology Volume 27, The University of California Press, 1925.
Davidson, Carlos. Booklet to the CD Frog and Toad Calls of the Pacific Coast - Vanishing Voices. Cornell Laboratory of Ornithology, 1995.
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The following status listings come from the Special Animals List which is published by the California Department of Fish and Wildlife.
These listings are labelled as refering to native, not introduced, California populations (however, the Natureserve and IUCN Global rankings must apply to non-California populations.)
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Organization
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Status Listing
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| U.S. Endangered Species Act (ESA) |
None |
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| California Endangered Species Act (CESA) |
None |
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| California Department of Fish and Wildlife |
DFG:SSC |
California Species of Special Concern |
| Bureau of Land Management |
None |
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| USDA Forest Service |
USFS:S |
Sensitive |
| Natureserve Global Conservation Status Ranks |
G5 S2 |
Secure |
World Conservation Union - IUCN Red List
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IUCN:LC |
Least Concern |
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