It's been a time of desperate measures. For example, after Southern Illinois University researcher Karen Lips and colleagues reported fungus-related declines in Costa Rica and Panama in the late 1990s, they began mapping chytrid's path and predicting its victims. By 2000, teams were grabbing up animals from the most vulnerable species to stash them away—at zoos, at hotels, anywhere temporary space could be carved out for stacks of aquariums. Sick frogs were treated and quarantined. Many were exported (with much political wrangling) to U.S. zoos, while a Panamanian facility was built to house nearly a thousand animals. So began the Amphibian Ark, a growing international venture aimed at keeping at least 500 species in captivity for reintroduction when—if—the crisis is resolved. But the task is immense and expensive, and there's no guarantee how many healthy wild places will be left for amphibians to recolonize.
The tropics, where conditions foster high amphibian biodiversity, have seen the most dramatic declines. But more temperate climates haven't been spared. Consider the cold, upper reaches of the Sierra Nevada of California. Here, at 11,000-foot-high Sixty Lake Basin, stands a stark paradise of granite towers made famous through the lens of Ansel Adams, where alpine lakes once roiled in summer with hearty frog populations. The most common species is the mountain yellow-legged frog—subtly pretty, tinged yellow on torso and limbs, spotted brown and black. But recently this palm-size frog has been hard to find.
A slender man with a camper's stubble and a soft demeanor squats at the side of pond number 100, bordered by stoic rock walls and edged with pink mountain heather and tangled grasses. Vance Vredenburg is a biologist at San Francisco State University, and he's been studying the mountain yellow-legged frog for 13 years, slumming in a tent on the mountainside for weeks at a time as he monitors 80 different study lakes. Today, mosquito net balled up around his neck, he contemplates ten dead frogs, stiff-legged, white bellies going soft in the sun.
"It wasn't long ago when you walked along the bank of this pond," he recalls, "a frog leapt at every other step. You'd see hundreds of them alive and well, soaking in the sun in a writhing mass." But in 2005, when the biologist hiked up to his camp anticipating another season of long-term studies, "there were dead frogs everywhere. Frogs I'd been working with for years, that I'd tagged and followed through their lives, all dead. I sat down on the ground and cried."
Vredenburg's biggest remaining study population, in pond number 8, has about 35 adults. Most of the rest of the animals he's known in this place are gone. What happened here is the perfect example of those multiple punches—a case study of how a thriving species can get knocked to its knees.