For kids from fourth grade up.
California Red-Legged Frog
Threatened. This means that we are worried about the species,
but it is not in danger of dying out right now.
The California red-legged frog is the largest native
frog in the western United States. It is from 4 to 13 centimeters long. (1.5 to 5 inches).
The abdomen and hind legs of adults are largely red. The back has
small black flecks and larger irregular dark blotches. These have indistinct outlines on a brown, gray, olive, or reddish background color.
Tadpoles (larvae) are from 14 to 80 mm long.
(0.6 to 3 inches) The tadpoles are dark brown and yellow with darker spots.
Highly variable. Larvae probably eat algae. Invertebrates are
the most common food items of adults. Vertebrates, such as Pacific tree frogs and California mice,
are frequently eaten by larger frogs.
The frogs do best when they live in deep-water pools with dense stands of overhanging willows with a fringe of cattails.
San Francisco Bay area (including Marin County). Central coast.
Isolated populations in a few other places such as the Sierra Nevada.
The frogs breed from November through March.
Bullfrogs are a big problem.
Loss of habitat from the growth of cities and suburbs. Mining.
Overgrazing by cattle. Invasion of nonnative species such as bullfrogs. Diseases. Some recreation
Catching a CA red-legged frog requires special training and a permit.
Leave that to scientists. With a copy of Pond Life (See More Reading below), you can
identify lots of pond animals, including other frogs.
There are a few places where you may be able to see the red-legged frogs. Pt. Reyes National Seashore is one. It is also a wonderful
place to see other rare species. Many of these animals and wildflowers are listed as threatened
See What You Can Do to Help Wildlife and Plants (201 KB PDF) for ideas about how to help threatened and endangered species.
Pond Life: A Guide to Common Plants and Animals of North American Ponds and Lakes by George K. Reid. Golden Books. A tiny, inexpensive book that is a must for anyone studying ponds. Out of print but easy to find. Your library may have one.
CaliforniaHerps.com has lots of
information about snakes, lizards, frogs, turtles and salamanders. See their species account about the California red-legged frog.
Two fun sites with lots of good stuff:
The Froggy Page
All about frogs for kids and teachers
Words to Learn
Biologists who study snakes, frogs, turtles, salamanders and other reptiles and amphibians are called herpetologists.
We call the California red-legged frog Rana aurora draytonii. Scientific names are in Latin or Greek.
The ending draytonii after Rana aurora means
that this is a subspecies. Some herpetologists say that it is a separate
species. They call it just plain Rana draytonii.
Herpetologists call tadpoles (newborn frogs) larvae.