Rana draytonii (Herps (reptiles and amphibians))

Species Description

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 Parks: 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 own 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, 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 GGNP, 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.

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Conservation Action Item

Restore Frog Habitat:
Volunteer at Mori Point

The San Francisco Garter Snake is in dire need of good habitat. You can help restore the species’ habitats by working with the Golden Gate National Parks Conservancy to restore habitats at Mori Point.

Big Year Competitors have reported 3 sightings and taken 0 actions to help this species recover so far this year.

Trips

• Twain's Frog and the Beautiful Serpent
  Saturday, 17 Mar 2012, 10:00 - 12:00 Pacific Time (US & Canada)
• Hike for Twain's Frog and the Beautiful Serpent
  Sunday, 16 Sep 2012, 10:00 - 12:00 Pacific Time (US & Canada)