California
Rana aurora draytonii   1 - Carley Sweet, U.S. Fish & Wildlife Service; 2 - U.S. Fish & Wildlife Service | |
| Type of Animal: | Amphibians |
|---|---|
| Class: | Amphibia |
| Order: | Anura |
| Family: | Ranidae |
| Federal Status: | Threatened |
| State Status: | |
| Occurrence: | |
| Habitat: | Ponds,Forest,Woodland,Grassland,Streams,Marshes |
| Description: | California red-legged frogs are California's largest native frogs. Adults have been found that are over five inches in length! They are commonly identified by their voice, which sounds like a stuttering "r-r-r-r-r-r-rowr." By sight you can identify them by their dark face and white jaw stripe. These frogs can also be identified by the red coloring on the underside of their abdomen and lower legs, but since they are listed as federally threatened it is illegal to handle them. Tadpoles range from about one-half inch to three inches in length. They are dark brown and yellow with darker spots. California red-legged frogs require a dense riparian habitat with deep still or slow moving water. They prefer areas that have dense populations of willows and some cattails. Blackberry bushes also provide good hiding habitat for the frogs. During estivation, the California red-legged frog seeks out underground shelter. Estivation is a type of hibernation that occurs in the summer. They may estivate in a variety of habitats, including small mammal burrows, beneath leaf litter, in trees and logs that have fallen on the ground, etc. The estivation area may be up to 300 feet away from water. Estivation is extremely important to the survival of these frogs because it allows them to conserve their energy during the months when food and water are not readily available. California red-legged frogs breed from November to March. These frogs may lay between 750 and 5000 eggs in each egg mass. The eggs are laid shortly after heavy rainfall, so the height of the breeding season is in January and February. The eggs are dark brown in color and are usually found on the surface of the water attached to the vegetation. The eggs hatch within 14 days of being laid. Unfortunately, most of the tadpoles are eaten by predators. Those that manage to get away from their predators may live up to 10 years! |
| Effort: | "One of the biggest threats to California red-legged frogs is habitat reduction. Events such as reservoir construction take away prime habitat components. In addition, pollution changes the chemical balance of the water and can kill the frogs. If the salinity (amount of salt in the water) reaches 4.5 parts per million all of the eggs will die. At 7 parts per million all tadpoles will die. The Bureau of Land Management (BLM) works with other agencies to reduce herbicide use near ponds used by California red-legged frogs. They also work with the agencies to reduce salt runoff into those ponds. Bullfrogs are also a major threat to California red-legged frogs. Bullfrogs not only eat red-legged frogs, but they also compete for space and food. Trout are common predators of California red-legged tadpoles. The BLM removes any bullfrogs or bullfrog tadpoles that are found in California red-legged territory. BLM also monitors the trout population in an effort to maintain a balance that allows trout to use the streams without making a negative impact on the California red-legged tadpole population. The BLM also protects California red-legged frog habitat by maintaining roadside vegetation and emergent aquatic vegetation that provide shelter for the frogs and tadpoles. Maintaining roadside vegetation also decreases the amount of erosion, which helps keep the ponds clean. The public can help the Bureau of Land Management protect this species by reporting sightings (or hearings!) of either bullfrogs or California red-legged frogs and tadpoles. You can also help by not releasing unwanted pets into the wild and by helping to prevent pollution of ponds." |
| References: | Behler et al. 1979. National Audubon Society Field Guide to Reptiles and Amphibians. Stebbins 1985. Peterson Field Guide to Western Reptiles and Amphibians, Second Edition. Zeiner et al. (editors). 1988. California’s Wildlife, Volume I, Amphibians and Reptiles. |
| Other Sites: | U.S. Fish and Wildlife Service |
| Field Office(s): | Bakersfield; Barstow; Mother Lode; Palm Springs; Redding; Ukiah |