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Golden Gate National Recreation Area

Red-Legged Frog, Rana aurora draytonii

California Red-Legged Frog
Rana aurora draytonii

Photo © Sue Gardner

Listen to the California Red-Legged Frog's Call

Recording © Carlos Davidson, Director, San Francisco State University's Environmental Studies Program

Home >> Species >> California Red-Legged Frog

California Red-Legged Frog
Rana aurora draytonii

The California Red-Legged Frog is the largest frog native to the western United States.  For many years, it was considered one of two subspecies of the Red-Legged Frog, Rana aurora, with the boundary between the two subspecies just north of the Golden Gate National Recreation Area: for example, Point Reyes National Seashore can have individuals from both subspecies, as well as intergrades of the two. However, recent studies indicate that the California Red-Legged Frog is its Pond Restorationown species, Rana draytonii, and that the boundary between it and Rana aurora is much farther north. 

 The California Red-Legged Frog has been intertwined with California history and the lore of the West in several surprising ways.   Made famous as the title character of Mark Twain’s tale “The Celebrated Jumping Frog of Calaveras County,” it was a favorite competitor in jumping frog competitions—until the California Red-Legged Frog was displaced by species imported from other parts of the world.  It became a staple of the diet of the forty-niners during the California Gold Rush, and eventually became an item on the menu of San Francisco’s finest dining establishments.

Unfortunately, the California Red-Legged Frog has now been lost from over 70% of its historic range.  It is currently only found in select coastal drainages from Marin County south to Baja California Red-Legged FrogsCalifornia, with a few isolated populations in the Sierra Nevada and the Transverse ranges.  In 1996, the United States Fish and Wildlife Service listed the California Red-Legged Frog as a threatened species under the Endangered Species Act.

The threats facing the frog are numerous, and correspond to a global decline in amphibian species.  Urban encroachment on existing habitats, the construction of reservoirs and water diversions that destroy feeding and breeding habitats; pesticide runoff and drift disrupting the species’ endocrine systems; livestock grazing; and the introduction of invasive, colonial species that compete—and sometimes eat—the California Red-Legged Frog.

In the GGNRA, some of the best habitats remaining for the California Red-Legged Frog are at Mori Point in San Mateo County, where the species is eking out an existence along with another listed species, the San Francisco Garter Snake.  When the winter rains arrive, you can hike there at dusk and listen for the Frog’s unique call, as its tenuous cycle of life continues on.

Conservation Action Item

Biologists have published several studies showing a strong correlation between the loss of California Red-Legged Frogs and pesticide use. Amphibians such as frogs are also facing a world-wide decline, and pesticides and other toxins are believed to play a role in the global problem. You can help reduce the number of toxic chemicals and pesticides released into our environment by replacing household and garden pesticides and cleaners with earth-friendly products.

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Previous Comments

Posted by: Liam O'Brien | 2008-05-16 01:32:50

A wonderful day with the frog at Mori Point. Actually over six frogs were sighted grouped together along the creek. We were told this was very unusual behavior. Then got down into the creek and pulled trash -- right out of the creek I was looking at frogs in: a true connection to action/conservation/satisfaction.

 

Posted by: Mocrael | 2008-05-16 01:33:38

The Northern Red-Legged Frog is threatened in the Vancouver, BC Canada area also, due to habitat destruction and degradation by road building, residential and recreational development and overuse.

Also, the introduction of the Bullfrog has become a threat on Vancouver Island, across the water.

The real problem in my area lay with very little conservation and protection within municipal jurisdictions. Strong armed selfish-interest groups trump conservation efforts every time. Economics before ecology seems to be the mantra. I don't hold out much hope we can convince our muni authorities to honour the Year of the Frog. The wheeled locusts of the woods are considered to be the new stewards of the woods with their consummate "roman road" building and diverting of drainage.

Not good for the Northern Red-legged frog habitat up here -- sadly

 

Posted by: Steve Price | 2008-06-04 17:01:59

This was a very easy and fun sighting. We stood on the bridge near the golf course and peered into the water looking for frogs. Soon we'd spotted 3 or 4 good sized frogs.