In the 2012 President's Budget Request, the National Biological Information Infrastructure (NBII) is terminated. As a result, all resources, databases, tools, and applications within this web site will be removed on January 15, 2012. For more information, please refer to the NBII Program Termination page.
For more information about Amphibians nationwide, visit the NBII Amphibians Web site. There you can find further Web resources on amphibians and the diverse factors affecting amphibian populations globally.
To find out what frogs you are hearing, look up frog calls using the USGS Frog Call Lookup from the USGS Patuxent Wildlife Research Center. There you can learn to identify frog calls and quiz yourself using the frog call quizzes for your area.
Amphibians of California
California Red-legged Frog [Photo: Chris Brown, USGS]
Amphibians are a class of vertebrates with over 4,000 species. There are three orders of amphibians: salamanders and newts
(Urodela)
, frogs and toads
(Anura)
, and caecilians
(Apoda)
. Thought of as cold-blooded, amphibians are ectotherms, meaning they are unable to regulate their own body temperature independently of the temperature of their surroundings. Amphibians are generally small with thin skin permeable to air and water. With few exceptions, amphibians do not actively care for their young. In general, amphibian reproduction strategy consists of egg-laying and external fertilization of a large number of eggs in a moist or fully aquatic environment. Fertilized eggs develop into amphibian larvae that live part of their lives dependent on an aquatic environment requiring gills and specialized feeding habits. Following a pattern of development unique to amphibians, amphibian larvae undergo marked changes and metamorphose into an terrestrial form that lives on land. Typically, this metamorphosis is demonstrated by loss of gills, changes in overall appearance, and changes in diet.
California is home to 51 native amphibian species, 12 of which are listed as threatened or endangered by the State of California or federal government (Source: Atlas of the Biodiversity of California).
California is home to a variety of ecosystems which provide diverse terrestrial habitats and aquatic habitats, which amphibians depend on for reproduction. The San Diego Natural History Museum's Field Guide to Reptiles & Amphibians provides information about the life history and characteristics of many California amphibians, as well as photographs and checklists.
Other resources include:
California Herps: A Guide to the Reptiles and Amphibians of California
Arroyo Toad [Photo: San Diego Natural History Museum]
Arroyo Toad Bufo californicus
Description:The endangered Arroyo Toad is a frog 2-3 inches in length, characterized by symmetrical blotches on either side of the spine on top of its gray, green, or brown coloring. The toad does not have a stripe running down its back, and has a v-shaped white stripe between the eyes.
Life History:This locally migrant toad lays its eggs in gravelly, sandy, or muddy areas as well as among sticks and leaves, and in quiet shallow water. Juveniles disperse following the wet season. They are nocturnal and feed on ants, crickets, snails, beetles, and occasionally their own freshly hatched species. Larvae are thought to eat organic matter and algae.
Habitat:The toad is usually found in riparian areas where there are willow, cottonwood, and sycamore trees, and can occasionally be found in other habitats such as streams, small puddles, or ponds in evergreen forests.
Distribution:The Arroyo Toad is found from northern Baja California, Mexico to Monterey and San Luis Obispo counties, California.
Status:The Arroyo Toad has been listed as an endangered species because of habitat loss by the United States Fish and Wildlife Service since 1994.