The California Red-legged Frog

The California red-legged frog, Rana aurora draytonii, is a large frog growing up to 5 inches in length. It is listed as a federally threatened amphibian and has been reduced to habitat about 10 percent of its original range. They get their name from their reddish back legs and under belly. Their skin is usually a brownish-gray with dark spots and they have a white line at the top of their jaw.

The tend to emerge from their wintering habitat at the end of winter and beginning of spring to search for mates. The males croak out a song to attract females and the female will lay large egg clutches of anywhere from 2,000 to 5,000 eggs. It only takes the eggs one or two weeks to hatch, but it takes as long as 7 months for the tadpoles to complete their life cycle to become frogs. The tadpole period leaves them vulnerable to any number of predators such as birds, other frogs or fish. This is the reason the females lay so many eggs. The loss is huge and only a few can be expected to survive into adult hood.

As with most threatened and endangered species, loss of habitat in one form or another is the main cause for the red-legged frog's decline. Habitat loss can be from development, urban sprawl, or pollution. One cause of pollution is from pesticide use in agricultural areas. The pesticide is sprayed over the crops and then it washes into the streams and creeks during irrigation or storm events. Frogs are notoriously sensitive to pollution and are excellent indicators of the health of a water system. If you have frogs in a creek or stream, it's a healthy and clean water way.

Due to the declining population of the red-legged frog, the US Fish and Wildlife Service set aside areas of critical habitat to protect the species. The habitat needed by the frogs is a combination of water with deep pools and riparian areas (those areas located around rivers and creeks). The frogs need shrubs and brush for concealment and willows and cattails for egg laying. The frogs go into a form of hibernation called estivation during the hot summer weather and burrow beneath the leaf litter in the riparian zone. For this reason, biological surveys are needed before entering suspected habitat so the frogs are not stepped on during their dormant stage.

Because of their threatened status, the frogs are not to be touched, picked up or harmed in any manner. A permit is required before anyone is able to handle or relocate the frogs. If a project is proposed within red-legged frog habitat, the necessary permits will have to be applied for and fees paid. Some of these fees can be quite expensive, sometimes in the thousands of dollars. If any of the habitat is to be disturbed or damaged, a survey would be done first, and then mitigation done. Mitigation can be money or something like revegetating an area with native plants. The red-legged frog is an important native species and its loss could have devastating results to the local ecosystem.