Just What Good is a Toad?
A scientist and a jazz musician seek the answer
This week’s SNARL (Sierra Nevada Aquatic Research Laboratory) Lecture featured a scientist and a musician, both attempting to answer the question: What good is a toad?
First, the scientist: Starting in 2005, Dr. Eric Berlow led a team that gathered the first comprehensive data about where Yosemite Toads, which are listed as “threatened” under the Endangered Species Act, breed in Yosemite. They breed early in the spring in small, ephemeral pools fed by snowmelt. They live to be about twenty years old, and little is known about how they survive winter in the High Sierra, except that they don’t hibernate.
Since 2000, Yosemite Toads have been at the center of several major lawsuits over whether or not backcountry grazing by pack stock harms their habitat. In 2000, the High Sierra Hikers Association sued the Inyo and Sierra National Forests, claiming the agencies had failed to uphold the National Environmental Policy Act when they authorized special use permits for pack stations in the John Muir and Ansel Adams Wilderness Areas. The High Sierra Packers Association counter-sued, and the Inyo and Sierra National Forests lost because they only had anecdotal data regarding interactions between stock and toads.
“The problem with anecdotes is that you can always find another expert who will disagree,” said Berlow, who was promptly brought on to collect that data in Yosemite National Park. After years of research, he found no real correlation between the decline of toad populations and the presence of stock animals.
“So what good is a toad?” Berlow asked the audience. “People asked me that all the time, and I didn’t really find that science had a good answer. They don’t eat mosquitoes. If a toad goes extinct, what happens? Well, they aren’t a keystone species, nothing really eats them because they aren’t that palatable.” Berlow noted that their presence is an indicator of meadow health, but then that begs the question, what good is a meadow?
“Some of these high meadow ecosystems are the headwaters, the sources of water for San Francisco. They act like sponges, releasing water gradually into streams that flow to Hetch Hetcy Reservoir, which contains water so clean that it requires only filtration before it can be consumed,” said Berlow.
