Frog Survival
Rana muscosa; Mountain Yellow-legged Frog. Photo © 2004 William Flaxington.
JB: This Earth and Sky. Around now, researchers are wading through a small creek in California’s San Bernardino Mountains – the area hardest-hit by wildfires half a year ago.
DB: They’ll be listening for a sound that means survival for a species – the “plop” of mountain yellow legged frogs as the frogs jump into the water. Yellow-legged frogs were common in the San Bernardino Mountains – until flood control measures, beginning in the 1930s, rerouted interconnected streams into large concrete channels. Now one creek, called City Creek, holds – or held – the last population of these frogs.
JB: Frogs flee to the water during wildfires – but post-fire flooding might have finished them. Rain sweeps the loose sediment off the soil and washes everything – including frogs – downstream. In early November, when there were still frogs left, biologists netted a dozen and moved them to the LA Zoo. But this past Christmas day, the most massive flooding in decades washed the whole bottom of the channel downstream.
DB: If biologists don’t find any frogs in California’s City Creek soon, they might move some of the zoo frogs back in. And if any frogs have survived or can be made to survive in the wild, there’s a chance that they can repopulate. Their prey – aquatic insects – are already back. Special thanks today to the National Fish and Wildlife Foundation and to the US Forest Service. We’re Block and Byrd for Earth and Sky.
Mountain yellow-legged frog (State of California)
Author’s Notes:
In a natural system neighboring frogs would move back in. But now the streams are disconnected and there are no other frogs around anyway.
The following individual was interviewed for today’s show. Our thanks to:
Steve Loe
Forest Biologist
San Bernardino National Forest
Our thanks also to :
California Dept. of Fish and Game
California Interagency Wildlife Task Group
Additional Teacher Resources
California Department of Fish & Game, California Wildlife Habitat Relationships System: Mountain Yellow-legged Frog-
This site contains a scientific overview of the species distribution, abundance, habitat requirements, and life history of the mountain yellow-legged frog.
USDA Forest Service: Rana muscosa
This site provides a brief natural history of the mountain yellow-legged frog.
National Park Service, Natural Resources Year in Review-2001: Restoration of Mountain Yellow-legged frogs in Kings Canyon
The Mountain Yellow-legged Frog, Rana muscosa, is endemic to the Sierra Nevada and some mountains in southern California. It is the only large frog in the high Sierras and an important part of the alpine and sub-alpine environment where lakes are naturally free of fish. Historically, backcountry visitors could see hundreds of these frogs along the shores of individual lakes, and thousands of their tadpoles could be seen swimming in the clear water. Today they are rarely observed. This article explains why, and what is being done about it.
