ATLANTA JOURNAL-CONSTITUTION (Georgia) 10 April 08 Nature calls and frogs, scientists, answer (Mark Davis)
Monticello: The moon was just a sliver of silver in the immense indigo when the chorus started. It came from the shadows, where hardwoods are in bud.
Eep! Eep! Eep-eep-eep!...
Kristina Sorensen tilted her head. "Peepers," she said.
Then, just on the edge of a pond:
Snerf!
"Oh! A pickerel."
Click-click... click-click.
Sorensen smiled. "Cricket frog."
The sounds came from every corner of the night — melodious peeps and guttural coughs, metallic clicks and a banjo-like strumming. Sorensen didn't move.
Weh-k-k-k...
"Gray tree frog."
This is science in its nascent stages. Sorensen, a biologist with the state Department of Natural Resources, is helping catalog the sounds of Georgia's 31 frog species. The inventory of calls — what peeped, croaked or bellowed, where and when — will become part of the North American Amphibian Monitoring Program. This is the first year Georgia has participated in the count, overseen by the U.S. Geological Survey.
Wednesday night, Sorensen jumped in her state-owned Chevy pickup and made a 30-mile circuit through parts of Jasper and Putnam counties, about 65 miles east of Atlanta. The truck bumped down gravel and clay roads where a vehicle is so unusual that dogs barked when hers passed.
She stopped at 10 sites and spent five minutes at each, listening. This is a good time of the year to listen, too: It's mating season. The guys are calling to the girls from ditch and limb, from bog and log.
And the girls? Sorensen, 29, smiled again. "They're listening," she said.
The project began in January, when John Jensen, a DNR senior wildlife biologist, established 78 different routes charting frog sounds. The routes range from coastal plains to mountains.
"It seemed like a pretty good way to look at frog populations," he said.
Volunteers travel some of the routes, which average about 15 miles and have established stops. Other DNR workers, like Sorensen, agreed to venture into the night, clipboard in hand.
Sorensen, like others in the frog-listening program, had to pass a quiz before she could do an inventory. It's not always easy, say, to discern a Fowler's toad (Whehhhh) from an Eastern narrowmouth toad (Wehnnnn).
The listeners will make circuits three times this year, noting any changes in frog calls at each stop. In time, said Jensen, the state will know whether frog populations are flourishing or diminishing.
Worldwide, frogs are in trouble. Beset by habitat loss and a fatal fungus, some species have nearly vanished. Scientists are so concerned about amphibians that they declared 2008 the Year of the Frog.
Federal scientists hope the monitoring program will illuminate frogs' status in the United States, said Linda Weir, who oversees the national effort. More than 20 states, from the Southeast to the Midwest, are participating, she said.
"We want to better understand what is happening with frogs and toads," she said.
It will take time to learn how Georgia frogs are faring, Jensen said.
"We're just establishing a baseline [of data] now," said Jensen, a metro Atlanta native whose Jasper County home has a concrete frog squatting by its steps. "I'm probably going to be retired before they see some [population] trends in the state."
Wednesday's listening began about a half-hour after dusk in the Oconee National Forest. Sorensen pulled off a two-lane highway where a dock juts into Murder Creek. The moon, reflected in its black waters, looked like lightning. Fireflies flitted in branches furred with new growth.
For a moment, nothing. Then —
Eep! A far-off hello from a male peeper. Sorensen nodded. Eep! Another peeper, somewhere in the trees, responded.
Five minutes later, Sorensen made the first notations in her log. The truck spun a few rocks as it bounced back onto the two-lane, turned left onto a gravel road, and plunged into the depth of night.
The second stop, along a road barely wide enough to allow two pickups to pass, was hardly more than a ditch. Sorensen threw the truck in park and stepped into the dark. Stars twinkled like scattered diamonds.
Whehhhhhh...
"Fowler's toads," Sorensen declared. "A full chorus."
Moments later, the truck was moving again, twin beams of light poking holes in complete darkness. "I think," said Sorensen, raised on the east coast of Florida, "that we are officially in the sticks."
The sticks abounded with life. A coyote screamed in the distance at one stop, a dark stretch of roadway where a distant house was the only sign of human activity. Something crashed through the brush at a site were trees hung over the road. At another stop: Aaaaa-Ohhhh... Bullfrog? Sorensen shook her head. "Bull," she said.
"I like this," Sorensen said, her face illuminated in the pale green lights of the Chevy's dash. "I have a passion for preserving our natural resources."
The listening session wound up at Charlie Elliott Wildlife Center in Jasper County, where Sorensen put down her clipboard to eavesdrop on couple of barred owls. Their hoots echoed in the woods. They sounded like two old pals saying hello.
The evening's total? Sorensen detected peepers, gray tree frogs, green frogs, American toads and Fowler's toads. She also heard the lone calls of a cricket frog and the pickerel that spoke from the edge of the pond.
"Got it," she said. "Time to go."
Her pickup headed back to the highway, red lights blinking in the dark, while a silver moon cradled the stars.
Nature calls and frogs, scientists, answer