Near Miryang, South Korea: 35° 30' 43" N, 128° 44' 24" E
“I don’t like this place,” announces Jang Yikweon.
We’re hiking in a pretty little valley in rural South Korea, Jang and I, traversing a storybook landscape of electric green rice paddies, cozy farming hamlets, mossy hill forests, and fleets of puffy clouds burnished gold by the setting sun. In other words: a postcard of pastoral bliss.
“What’s not to like?” I huff.
“Listen,” replies Jang. “Do you hear that?”
I cock my ears. I discern the flap flap flap of white egrets ascending to roost for the night in tree boughs. I hear the gurgle of water in irrigation canals. Our footsteps crunch on a gravel path. Crickets trill.
“It’s the paddies,” Jang says. “There are no frog songs!”
I sigh. That’s Jang: a compact, friendly, bespectacled man in fit middle age, his face slightly creased by living and working outdoors. He is a leading zoologist and ecologist in South Korea who has spent years studying communications among insects, birds, amphibians, and mammals. Above all, Jang is a self-described frog man. He really likes frogs. He talks about frogs and to frogs all the time. He picks frogs up and holds them delicately in his palm. He worries about their fate. At the moment, he is studying the habits of two tree frog species, the endangered Dryophytes suweonensis and the more abundant Dryophytes japonicus. Jang worries that the overuse of pesticides and fertilizers may be imperiling both populations in local paddies.
“We have almost no natural wetlands left in Korea,” says Jang, a professor at Ewha University in Seoul. “Many of our remaining frogs survive only in wet rice fields. They must coexist with humans. They have no choice.”
A common frog, Pelophylax nigromaculatus, faces tough odds in South Korea. Jang Yikweon, an ecologist, is studying how frogs and humans interact in a world increasingly hostile to amphibians.
Paul Salopek
Indeed, frogs across the world have gotten the catastrophically short end of the stick in their long associations with humankind. A global frog die-off has alarmed environmentalists for decades.
The bleak metrics:
More than 40 percent of the world’s 8,000 amphibians, the class of animals to which frogs belong, have been in decline—often drastically—since the 1970s. This includes 200 frog species alone that have vanished from the face of the Earth. The causes are likely myriad and not fully understood, but they include habitat loss, a lethal fungal disease (Chytridiomycosis, possibly spread by human activity), climate change, water and airborne chemical pollutants (frogs have permeable skin), rising levels of UV radiation in the atmosphere, even light pollution (frogs are often nocturnal).
In South Korea, a frog’s prospects are particularly grim because the 52 million Homo sapiens ruling the country have altered the landscape, as people everywhere do, to suit their appetites. Asia’s economic boom has spawned new housing subdivisions, dams, highways, factories, and many thousands of square miles of mechanized, monoculture farming. Frogs have negotiated human selfishness, Jang notes, for at least 1,500 to 2,000 years; since the dawn of rice cultivation in Korea. But today, little wild habitat remains for frogs to escape to.
Hence, the focus of Jang’s muddy research: Thousands of hours of observing frogs in “artificial” swamps—farmers’ paddies.
For frogs in South Korea, rice fields are their last bastion.
Out of Eden Walk
“What makes plentiful japonicus succeed there?” Jang asks himself aloud, leading me at dusk from the city of Miryang to hunt for frogs at night in nearby rice fields. “And why doesn’t the rare suweonensis do as well?”
The answers, Jang hopes, might help humans and frogs coexist better. His data are preliminary and poignant.
Suweonensis, the endangered species, appears to prefer the centers of rice paddies because these are stable habitats, buffered from change: comfort zones for a “timid” frog species. The more abundant japonicus, on the other hand, does better at the edges of rice fields where the environment is unpredictable: a “bold” frog species advantaged in a fast-changing world. I am about to remark how such frog wisdom could apply also to people when a farmer hollers at us. She is elderly. Serenaded by Christian pop music burbling from a hand-held radio, she is out taking her evening constitutional. She demands to know what we’re doing splashing about, with headlamps, in her fallow rice paddies.
“We are looking for frogs,” Jang yells back.
“Looking for what?”
“Frogs.”
“Ah, frogs,” the farmer shrugs, walking on. “We used to fill barrels with them. We ate them back in the lean times.”
Happily, we find a few survivors. The small olive-colored frogs, all of them the more common japonicus, glisten like eyed jewels in my palm. Later, Jang will demonstrate for me his frog calls. He will smile when one frog calls back.
