In my home outside Yosemite, I would spend hours watching pacific chorus frogs nimbly leap from my windowsill, devour a passing moth, and then crawl back up the glass with their dainty, adhesive toepads.   One night I observed a frog and California mantid stare each other down; another day an alligator lizard and a frog shared the perch. After a couple of seasons, we built a small frog pond in the yard. Build it and the amphibians will come—the next week a California toad arrived, ambling to the water.

 Pacific Chorus Frog in Our PondOn my first thru hike on the John Muir Trail over a decade ago, I encountered a young man near Selden Pass, skipping happily down the trail. We hiked together for a couple of miles and he told me he was researching frogs in the Sierra Nevada. I scanned small ponds and creek beds with him for a few hours and he transmitted his delight of the amphibian world to me. Ever since, I have searched for frogs on my hikes, and am enchanted by all things froggy.

Yet frogs and other amphibians are disappearing from the Sierra Nevada—and the world—at an alarming rate. David Wake, professor of integrative biology at the University of California at Berkeley, recently commented about his study just published in the National Academy of Sciences journal. "There's no question that we are in a mass extinction spasm right now. Amphibians have been around for about 250 million years. They made it through when the dinosaurs didn't. The fact that they're cutting out now should be a lesson for us.”

Frog and California MantidThe Sierra Nevada Yellow-legged frog and the Southern Yellow-legged frog populations have recently declined a staggering 95% to 98% (that is not a typo!) in the Sierra Nevada—and the diminished populations occur even in the boundaries of refuges such as Yosemite National Park.

What is killing the frogs? Global warming, pollution, and habitat reduction are all contributing to amphibian decline, but the most recent villain in this scenario is the deadly chytrid fungus, which has wiped out entire populations. Some research links the rapid spread of the fungus to the effects of climate change.

Defenders of Wildlife featured the article,” Slipping Away: Frogs, Salamanders, and Other Amphibians Are Sliding Into Oblivion” in its spring issue of Defenders. In the piece, Kevin Zippel, program officer for the conservation group Amphibian Ark, stresses the seriousness of this issue: “It sounds like hyperbole, but really this is the greatest conservation challenge that humanity has ever faced.”